SAB Biotherapeutics, Inc.

Notes to condensed consolidated FINANCIAL statements (Unaudited)

(1) Nature of Business

SAB Biotherapeutics, Inc., a Delaware corporation (“SAB” or “SAB Biotherapeutics”, and together with its subsidiaries, the “Company”), is a clinical-stage biopharmaceutical company focused on the development of human polyclonal immunotherapeutic antibodies, or human immunoglobulins (“hIgG”), to address immune system disorders and infectious diseases. The Company’s antibodies are both target-specific and polyclonal, meaning they are comprised of multiple hIgGs and can bind to multiple sites on specific immunogens, making them ideally suited to address the complexities associated with many immune-mediated disorders. The Company’s lead candidate, SAB-142 is a human anti-thymocyte globulin (“ATG”) focused on preventing or delaying the progression of type 1 diabetes (“T1D”).

Australian Research and Development Tax Credit

In June 2023, the Company formed a new subsidiary in Australia, SAB BIO PTY LTD, a proprietary limited company (“SAB Australia”), primarily to conduct preclinical and clinical activities for product candidates. SAB Australia’s research and development activities qualify for the Australian government’s tax credit program, which provides a 48.5% credit for qualifying research and development expenses.

Liquidity

As of March 31, 2026, the Company had an accumulated deficit of$129.8 million. The Company anticipates that it will continue to generate losses for the foreseeable future and expects the losses to increase as the Company continues the development of, or seeks regulatory approvals for product candidates, and begins commercialization of products. As a result, the Company will require additional capital to fund operations in order to support long-term plans.

Based on the Company’s current level of operating expenses, existing resources will be sufficient to cover operating cash needs through at least the twelve months following the date of this report. In the future, the Company may seek additional funding through a combination of equity or debt financings, or other third-party financing, collaborative or other funding arrangements.

(2) Summary of Significant Accounting Policies

A summary of the significant accounting policies applied in preparation of the accompanying condensed consolidated financial statements is set forth below.

Basis of presentation

The unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles accepted in the United States of America (“GAAP”) for interim financial statements and the rules of the Securities and Exchange Commission (“SEC”) applicable to interim financial statements. Certain information or footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, pursuant to the rules and regulations of the SEC for interim financial reporting. Accordingly, they do not include all the information and footnotes necessary for a complete presentation of financial position, results of operations, or cash flows. The accompanying unaudited condensed consolidated financial statements have been prepared by management without audit and should be read in conjunction with our audited consolidated financial statements, including the notes thereto, appearing in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025. In the opinion of management, all adjustments necessary for a fair presentation of the consolidated financial position, consolidated results of operations and other comprehensive loss and consolidated cash flows, for the periods indicated, have been made. The results of operations for the three months ended March 31, 2026 are not necessarily indicative of operating results that may be achieved over the course of the full year.

Emerging growth company status

The Company is an “emerging growth company,” as defined in Section 2(a) of the Securities Act of 1933, as amended (the “Securities Act”), as modified by the Jumpstart our Business Startups Act of 2012, (the “JOBS Act”), and it may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies including, but not limited to, not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act, reduced disclosure obligations regarding executive compensation in its periodic reports and proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and stockholder approval of any golden parachute payments not previously approved.

Further, Section 102(b)(1) of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that a company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging growth companies but any such election to opt out is irrevocable. The Company has elected not to opt out of such extended transition period which means that when a standard is issued or revised and it has different application dates for public or private companies, the Company, as an emerging growth company, can adopt the new or revised standard at the time private companies adopt the new or revised standard. This may make comparison of the Company’s financial statements with another public company which is neither an emerging growth company nor an emerging growth company which has opted out of using the extended transition period difficult or impossible because of the potential differences in accounting standards used.

Principles of consolidation

The accompanying condensed consolidated financial statements include the results of the Company and its wholly owned subsidiaries, SAB Sciences, Inc., Diversity Therapeutics, Inc., SAB LLC, SAB Capra, LLC, Aurochs, LLC, and SAB Australia. Intercompany balances and transactions have been eliminated in consolidation.

Significant risks and uncertainties

The Company’s operations are subject to a number of factors that can affect its operating results and financial condition. Such factors include, but are not limited to, the results of research and development efforts, clinical trial activities of the Company’s product candidates, the Company’s ability to obtain regulatory approval to market its product candidates, competition from products manufactured and sold or being developed by other companies, and the Company’s ability to raise capital.

The Company currently has no commercially approved products and there can be no assurance that the Company’s research and development will be successfully commercialized. Developing and commercializing a product requires significant time and capital and is subject to regulatory review and approval as well as competition from other biotechnology and pharmaceutical companies. The Company operates in an environment of rapid change and is dependent upon the continued services of its employees and obtaining and protecting intellectual property.

Use of estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses and the disclosure of contingent assets and liabilities in the financial statements. The Company has used significant estimates in its determination of stock-based compensation assumptions, determination of the fair value of the Private Placement Warrant liabilities, determination of the incremental borrowing rate (“IBR”) used in the calculation of the Company’s right of use assets and lease liabilities, estimation of clinical and other accruals and the valuation allowance on deferred tax assets. Actual amounts realized may differ from these estimates.

Fair Value Measurements

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The following fair value hierarchy classifies the inputs to valuation techniques that would be used to measure fair value into one of three levels:

Level 1: Unadjusted quoted prices in active markets for identical assets or liabilities.

Level 2: Inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active.

Level 3: Unobservable inputs that reflect the reporting entity’s own assumptions.

Certain of the Company’s financial instruments are not measured at fair value on a recurring basis but are recorded at amounts that approximate their fair value due to the short-term nature of their maturities, such as cash and cash equivalents, accrued interest receivable, accounts payable, notes payable, accrued expenses and other current liabilities.

The Company accounts for warrants to purchase its common stock par value of $0.0001 per share (its “common stock”) pursuant to Accounting Standards Codification (“ASC”) Topic 470, Debt(“ASC 470”), and ASC Topic 480, Distinguishing Liabilities from Equity (“ASC 480”), and classifies warrants for common stock as liabilities or equity. The warrants classified as liabilities are reported at their estimated fair value (see Note 11, Fair Value Measurements) and any changes in fair value are reflected in other income

(expense). The warrants classified as equity are reported at their estimated relative fair value with no subsequent remeasurement. The Company’s outstanding warrants are discussed in more detail in Note 10, Warrants.

Deferred Issuance Costs

The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred issuance costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in shareholders’ equity as a reduction of additional paid-in capital generated as a result of the issuance.

The Company didnot have any deferred issuance costs as of March 31, 2026. As of December 31, 2025, the Company had$150 thousand of deferred issuance costs, related to the Company’s sales agreement with UBS Securities LLC. The sales agreement is discussed further in Note 8, Stockholders’ Equity.

Cash, cash equivalents, and restricted cash

Cash and cash equivalents are comprised of cash and highly liquid investments with original maturities of 90 days or less at the date of purchase. Cash equivalents consist primarily of exchange-traded money market funds and U.S. treasury securities.

The Company is exposed to credit risk in the event of default by the financial institutions or the issuers of these investments to the extent the amounts on deposit or invested are in excess of amounts that are insured.

Short-term and long-term investments

The Company accounts for investments in accordance with ASC Topic 320, Investments - Debt and Equity Securities. Management determines the appropriate classification of its investments at the time of purchase and reevaluates such determinations at each reporting period.

At March 31, 2026, the Company’s short-term and long-term investments consisted of U.S. treasury securities with original maturity exceeding 90 days, and investments in exchange traded mutual funds. The Company classifies these securities as current and non-current. The Company considers all of its securities for which there is a determinable fair market value, and there are no restrictions on the Company’s ability to sell within the next twelve months, as available-for-sale securities.

The Company recognizes the change in fair value of available-for-sale equity securities within other income in the condensed consolidated statements of operations and comprehensive loss, and available-for-sale debt securities are measured at fair value with unrealized gains and losses reported in accumulated other comprehensive income (loss) in the condensed consolidated balance sheets.

The Company reviews its investments at each reporting date to identify and evaluate whether a decline in fair value below the amortized cost basis of available-for-sale debt securities is due to credit-related factors and determines if such unrealized losses are the result of credit losses that require impairment. The Company records an allowance for credit losses on available-for-sale debt securities when a decline in fair value is determined to be credit-related, rather than recording a direct write-down of the investment's amortized cost. Factors considered in determining whether an unrealized loss is the result of credit-related factors include the extent to which the fair value is less than the cost basis, any changes to the rating of the security by a rating agency, the financial condition and near-term prospects of the issuer, any historical failure of the issuer to make scheduled interest or principal payments, any adverse legal or regulatory events affecting the issuer or issuer’s industry, any significant deterioration in economic condition and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value.

The Company didnot recognize any credit losses on its short-term and long-term investments during thethree months ended March 31, 2026 and 2025.

Concentration of credit risk

The Company maintains its cash and cash equivalent balances in the form of business checking accounts and money market accounts, the balances of which, at times, may exceed federally insured limits. Although the Company currently believes that the financial institutions with whom it does business will be able to fulfill their commitments to the Company, there is no assurance that those institutions will be able to continue to do so. The Company has not experienced any credit losses associated with its balances in such accounts for the three months ended March 31, 2026 and 2025.

Lease liabilities and right-of-use assets

The Company is party to certain contractual arrangements for equipment, lab space, and an animal facility, which meet the definition of leases under Financial Accounting Standards Board (“FASB”) ASC Topic 842, Leases(“ASC 842”). In accordance with ASC 842, the Company recorded right-of-use assets and related lease liabilities for the present value of the lease payments over the lease terms. The Company’s IBR was used in the calculation of its right-of-use assets and lease liabilities.

The Company elected not to apply the recognition requirements of ASC 842 to short-term leases, which are deemed to be leases with a lease term of twelve months or less. Instead, the Company recognizes lease payments in the condensed consolidated statements of operations and comprehensive loss on a straight-line basis over the lease term and variable payments in the period in which the obligation for these payments was incurred. The Company elected this policy for all classes of underlying assets.

Research and development expenses

Expenses incurred in connection with research and development activities are expensed as incurred. These include licensing fees to use certain technology in the Company’s research and development projects, fees paid to consultants and various entities that perform certain research and testing on behalf of the Company, and expenses related to animal care, research-use equipment depreciation, salaries, benefits, and stock-based compensation granted to employees in research and development functions.

During the three months ended March 31, 2026 and 2025, the Company had contracts with multiple contract research organizations (“CRO”) to complete studies as part of research grant agreements. These costs include upfront, milestone and monthly expenses as well as reimbursement for pass through costs. All research and development costs are expensed as incurred except when the Company is accounting for nonrefundable advance payments for goods or services to be used in future research and development activities. In these cases, these payments are capitalized at the time of payment and expensed in the period the research and development activity is performed. As actual costs become known, the Company will adjust the accrual; such changes in estimate may result in material changes in the Company’s clinical study accrual, which could also materially affect reported results of operations. For the three months ended March 31, 2026 and 2025, there were no material adjustments to the Company’s prior period estimates of accrued expenses for clinical trials.

Property, Plant and Equipment

The Company records property, plant, and equipment at cost less depreciation and amortization. Depreciation is calculated using straight-line methods over the following estimated useful lives:

Repairs and maintenance expenses are expensed as incurred.

Impairment of long-lived assets

The Company reviews the recoverability of long-lived assets, including the related useful lives, whenever events or changes in circumstances indicate that the carrying amount of a long-lived asset may not be recoverable. If necessary, the Company compares the estimated undiscounted future net cash flows to the related asset’s carrying value to determine whether there has been an impairment. If an asset is considered impaired, the asset is written down to fair value, which is based either on discounted cash flows or appraised values in the period the impairment becomes known. The Company believes that long-lived assets are recoverable, andno impairment was deemed necessary, during thethree months ended March 31, 2026 and 2025.

Stock-based compensation

FASB ASC Topic 718, Compensation– Stock Compensation, prescribes accounting and reporting standards for all share-based payment transactions in which employee and non-employee services are acquired. The Company recognizes compensation cost relating to stock-based payment transactions using a fair-value measurement method, which requires all stock-based payments to employees, directors, and non-employee consultants, including grants of stock options, to be recognized in operating results as compensation expense based on fair value over the requisite service period of the awards. The Company determines the fair value of common stock based on the closing market price at closing on the date of the grant.

In determining the fair value of stock-based awards, the Company utilizes the Black-Scholes option-pricing model, which uses both historical and current market data to estimate fair value. The Black-Scholes option-pricing model incorporates various assumptions, such as the value of the underlying common stock, the risk-free interest rate, expected volatility, expected dividend yield, and expected life of the options. For awards with performance-based vesting criteria, the Company estimates the probability of achievement of the performance criteria and recognizes compensation expense related to those awards expected to vest. No awards may have a term in excess often years. Forfeitures are recorded when they occur. Stock-based compensation expense is classified in the condensed consolidated statements of operations based on the function to which the related services are provided. The Company recognizes stock-based compensation expense over the vesting period.

Income taxes

Deferred income taxes reflect future tax effects of temporary differences between the tax and financial reporting basis of the Company’s assets and liabilities measured using enacted tax laws and statutory tax rates applicable to the periods when the temporary differences will affect taxable income. When necessary, deferred tax assets are reduced by a valuation allowance, to reflect realizable value, and all deferred tax balances are reported as long-term on the condensed consolidated balance sheets. Accruals are maintained for uncertain tax positions, as necessary.

The Company uses a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken, or expected to be taken, in a tax return. The Company has elected to treat interest and penalties related to income taxes, to the extent they arise, as a component of income taxes.

Foreign Currency Translations and Transactions

Assets and liabilities of the Company's foreign subsidiary are translated at the period-end exchange rate. Operating results of the Company's foreign subsidiary are translated at average exchange rates during the period. Translation adjustments have no effect on net income (loss) and are included in “Accumulated other comprehensive income (loss)” in the accompanying Condensed Consolidated Balance Sheets.

Comprehensive loss

Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with stockholders. The components of comprehensive loss for the three months ended March 31, 2026 and 2025 consist of foreign currency translation adjustments from its subsidiaries not using the U.S. dollar as their functional currency, and unrealized gains and losses on available-for-sale debt securities. During the three months ended March 31, 2026, $47 thousand of net realized gains was reclassified from accumulated comprehensive income (loss) to other income. The Company didnot reclassify any realized gains or losses for thethree months ended March 31, 2025.

Litigation

From time to time, the Company is involved in legal proceedings, investigations and claims generally incidental to its normal business activities. In accordance with U.S. GAAP, the Company accrues for loss contingencies when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Legal costs in connection with loss contingencies are expensed as incurred.

Earnings per share

In accordance with ASC 260, Earnings per Share(“ASC 260”), basic net income (loss) per share attributable to common stockholders is computed by dividing net income (loss) attributable to common stockholders by the weighted-average number of common stock outstanding during the period. Diluted net income (loss) per share attributable to common stockholders is computed by dividing the diluted net income (loss) attributable to common stockholders by the weighted-average number of common stock outstanding for the period including potential dilutive common shares such as stock options and convertible preferred stock. See Note 4, Earnings per share, for further details.

Segment reporting

In accordance with ASC 280, Segment Reporting, the Company’s business activities are organized intoone reportable segment, as only the Company’s operating results in their entirety are regularly reviewed by the Company’s chief operating decision maker to make decisions about resources to be allocated and to assess performance.

Australian Research and Development Tax Credit

The Company recognizes other income from Australian research and development incentives when there is reasonable assurance that the income will be received, the relevant expenditure has been incurred, and the consideration can be reliably measured. The research and development incentive is one of the key elements of the Australian Government’s support for Australia’s innovation system and is supported by legislative law primarily in the form of the Australian Income Tax Assessment Act 1997, as long as eligibility criteria are met. Under the program, a percentage of eligible research and development expenses incurred by the Company through its subsidiary in Australia are reimbursed. The Company recognized$0.1 million and$0.4 million in tax credit income for the three months ended March 31, 2026 and 2025, respectively.

Managementhas assessed the Company’s research and development activities and expenditures to determine which activities and expenditures are likely to be eligible under the research and development incentive regime described above. At each period end, management estimates the refundable tax offset available to the Company based on available information at the time and it is included in other income in the condensed consolidated statements of operations and comprehensive loss.

(3) New accounting standards

Accounting Pronouncements Not Yet Adopted

In November 2024, the FASB issued ASU 2024-03, “Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Topic 220)”. ASU 2024-03 requires additional disclosure in the notes to financial statements of specified information about certain expenses such as purchases of inventory, employee compensation, depreciation, intangible asset amortization, and depreciation and other expenses which are presented in the face of the income statement within continuing operations. This ASU is effective for annual periods beginning after December 15, 2026, and interim periods within annual periods beginning after December 15, 2027, with early adoption permitted. The Company is currently evaluating the impact of adopting this ASU on its condensed consolidated financial statements and disclosures.

(4) Earnings per share

Since the Company reported a net loss for the three months ended March 31, 2026 and 2025, it was required by ASC 260 to use basic weighted-average shares outstanding when calculating diluted net loss per share for the three months ended March 31, 2026 and 2025, as the potential dilutive securities are anti-dilutive.

The following is a reconciliation of the numerator and denominator used to calculate basic earnings per share and diluted earnings per share for thethree months ended March 31, 2026 and 2025:

Included within weighted average common shares outstanding for the three months ended March 31, 2026, are 2,753,246 common shares issuable upon the exercise of pre-funded warrants, as the warrants are exercisable at any time for nominal consideration, and, as such, the shares are considered outstanding for the purpose of calculating basic and diluted net loss per share attributable to common stockholders.

The Company’s other potentially dilutive securities, which include stock options, restricted stock awards, common stock warrants, earnout shares, and contingently issuable earnout shares have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect:

(1)

Contained within common stock warrants are the 575,000 shares of common stock underlying public warrants (the “Public Warrants”),20,860 shares of common stock underlying warrants held by assignees of Big Cypress Holdings, LLC (the “Private Placement Warrants”),30,000 shares underlying warrants held by Ladenburg Thalmann & Co. Inc. (the “Ladenburg Warrants”),736,337 shares underlying warrants issued to the investors in the December 2022 Private Placement (the “the PIPE Warrants”),21,091 shares underlying warrants issued to the placement agent in the December 2022 Private Placement (the “PIPE Placement Agent Warrants”), and 850,119 shares underlying the Preferred PIPE Placement Agent Warrants issued to the placement agent in the September 2023 Offering. See Note 10, Warrantsfor further details on the Company’s outstanding warrants.

(2)

Represents 4,504,824 and 6,669,742 shares of common stock underlying 28,380 and 42,019 issued and outstanding shares of Series A-2 Preferred Stock, for the three months ended March 31, 2026 and 2025, respectively. See Note 8, Stockholders’ Equity for further details on the Company’s preferred stock.

(3)

Represents 17,002,381 shares of common stock underlying 107,115 outstanding Preferred Tranche C Warrants (as defined below) for thethree months ended March 31, 2026. See Note 10, Warrants for further details on the Company’s outstanding warrants.

(4)

Represents 50,000,000 and 98,300,000 shares of common stock underlying the Release Date Warrants and Enrollment Warrants, respectively, for the three months ended March 31, 2026.

(5) Property, plant and equipment

As of March 31, 2026 and December 31, 2025, the Company’s property, plant and equipment was as follows:

Depreciation and amortization expense was$0.7 million for the three months ended March 31, 2026 and$0.8 million for the three months ended March 31, 2025.

(6) Leases

The Company has an operating lease for lab space from Sanford Health, under a lease that started in June 2014 and initially ended in June 2019, at which time the lease was extended through August 2024. This lease was renewed in January 2025 for afive-year-term ending on December 31, 2029. This lease can be terminated withone-year advance written notice and does not include an option to extend beyond the life of the current term. The lease costs are approximately$50 thousand permonth through 2025, with an annual increaseof 2% through 2029. The lease does not provide an implicit rate, and, therefore, the Company used an IBR of 9.90% as the discount rate when measuring the operating lease liability. The Company estimated the IBR based upon comparing interest rates available in the market for similar borrowings and the credit quality of the Company.

The Company entered into a lease for office, laboratory, and warehouse space in November 2020, as amended in July 2022, and renewed in November 2023. This renewed lease has a 3-year term, with options to extend for 3 additional periods of 3 years each. The options were not included in the right of use calculation as it was unclear as to whether or not the location will meet the Company’s requirements beyond the next three years. The lease costs are$31 thousand per month for the November 2023 lease renewal. The Company used an IBR of 8.14% as the discount rate when measuring the operating lease liability for the November 2023 lease renewal. The Company estimated the IBR based upon comparing interest rates available in the market for similar borrowings and the credit quality of the Company.

In April 2024, the Company entered into a lease for 1,272 square feet of office space in Miami Beach, Florida. The initial term was 62 months, with monthly payments of approximately$7 thousand through 2024 and annual escalations of 4% through 2029. The lease liability was measured using an IBR of 7.12%. In September 2025, the Company terminated this lease and entered into a new lease for expanded space totaling 3,099 square feet in the same location. The new lease commenced in January 2026 with a 60-month term, monthly payments of approximately$17 thousand through 2026, and annual escalations of 3% through 2030. The new lease liability was measured using an IBR of 14.90%. The Company estimated the IBR based upon comparing interest rates available in the market for similar borrowings and the credit quality of the Company.

The Company has the following finance leases:

•

In December 2018, the Company entered into a finance lease with Dakota Ag Properties for a new animal facility which includes the surrounding land. The facility and the land have been accounted for as separate lease components. The lease is based upon payback of $4 million in construction costs, with a 20-year term at an interest rate of 8%. The monthly payment for this lease is $34 thousand. The Company has the option to purchase the asset at any time during the term of the lease for the balance of the unamortized lease payments.

The lease agreements do not require material variable lease payments, residual value guarantees or restrictive covenants.

The amortizable lives of the operating lease assets are limited by their expected lease terms. The amortizable lives of the finance lease assets are limited by their expected lives, as the Company intends to exercise the purchase options at the end of the leases. The following is the estimated useful lives of the finance lease assets:

The Company’s weighted-average remaining lease term and weighted-average discount rate for operating and finance leases as of March 31, 2026 and December 31, 2025 are:

The table below reconciles the undiscounted future minimum lease payments under non-cancelable leases with terms of more than one year to the total lease liabilities recognized on the condensed consolidated balance sheets as of March 31, 2026:

Operating lease expense was approximately$301 thousand for the three months ended March 31, 2026, and$268 thousand for the three months ended March 31, 2025. Operating lease costs are included within research and development expenses on the condensed consolidated statements of operations and comprehensive loss.

Finance lease costs for the three months ended March 31, 2026 included approximately$22 thousand in right-of-use asset amortization and approximately$63 thousand of interest expense.

Finance lease costs for the three months ended March 31, 2025 included approximately$22 thousand in right-of-use asset amortization and approximately$66 thousand of interest expense. Finance lease costs are included within research and development expenses on the condensed consolidated statements of operations and comprehensive loss.

Cash payments under operating leases were approximately$280 thousand for the three months ended March 31, 2026. Cash payments under finance leases were approximately$100 thousand for the three months ended March 31, 2026.

Cash payments under operating leases were approximately$213 thousand for the three months ended March 31, 2025. Cash payments under finance leases were approximately$100 thousand for the three months ended March 31, 2025.

(7) Accrued Expenses and Other Current Liabilities

As of March 31, 2026 and December 31, 2025, accrued expenses and other current liabilities consisted of the following:

(8) Stockholders’ Equity

Authorized and Outstanding Capital Stock

The total number of shares of the Company’s authorized capital stock is 810,000,000. The total amount of authorized capital stock consists of 800,000,000 shares of common stock and 10,000,000 shares of preferred stock. As of March 31, 2026,75,744,576 shares of common stock,28,380 shares of Series A Preferred Stock and 587,879 shares of Series B Preferred Stock were outstanding.

Series A Preferred Stock and Warrants

On September 29, 2023, the Company entered into a securities purchase agreement (the “September 2023 Purchase Agreement”) with certain accredited investors, pursuant to which the Company agreed to issue and sell, in a private placement (the “September 2023 Offering”), (i)7,500 shares of Series A-1 Convertible Preferred Stock, par value $0.0001 per share (the “Series A-1 Preferred Stock”), (ii) tranche A warrants (the “Preferred Tranche A Warrants”) to acquire shares of Series A-1 Preferred Stock or Series A-3 Preferred Stock, par value $0.0001 per share, (iii) tranche B warrants to acquire shares of Series A-3 Preferred Stock, par value $0.0001 per share (the “Preferred Tranche B Warrants”), and (iv) tranche C warrants to purchase Series A-3 Preferred Stock, par value $0.0001 per share (the “Preferred Tranche C Warrants” and together with the Preferred Tranche A Warrants, and Preferred Tranche B Warrants, the “Preferred Warrants”). The Series A-1 Preferred Stock, Series A-2 Preferred Stock, and Series A-3 Preferred Stock are collectively referred to in this section as the “Series A Preferred Stock.”

During the fourth quarter of 2023, holders exercised Preferred Tranche A Warrants to purchase an aggregate of 59,654 shares of Series A-1 Preferred Stock for gross proceeds of approximately $59.65 million. Unexercised Preferred Tranche A Warrants, together with the associated Tranche B Warrants, were forfeited or cancelled in accordance with the terms of the September 2023 Purchase Agreement. Preferred Tranche C Warrants remain outstanding and exercisable until the five (5) year anniversary of their exercisability date.

The Company issued an aggregate of 67,154 shares of Series A-1 Preferred Stock in connection with the September 2023 Offering and the exercise of the Preferred Tranche A Warrants.

Following receipt of required stockholder approval,24,918 shares of Series A-1 Preferred Stock were automatically converted into an aggregate of 3,954,674 shares of common stock at a conversion price of $6.30 per share (approximately 158.8 shares of common stock for each share of Series A-1 Preferred Stock). The remaining 42,236 shares of Series A-1 Preferred Stock were converted into an equal number of shares of Series A-2 Preferred Stock, which are convertible into common stock at the same conversion price of $6.30 per share, subject to certain beneficial ownership limitations as set forth in the Certificate of Designation of Preferences, Rights and Limitations of the Series A Convertible Voting Preferred Stock (the “Certificate of Designation”). There wereno Series A-2 Preferred stock converted for thethree months ended March 31, 2026 and 13,639 shares of Series A-2 Preferred Stock were converted into 2,164,918 shares of common stock during the twelve months ended December 31, 2025.

Holders of Series A Preferred Stock are entitled to receive dividends on an as-converted-to-common-stock basis and to vote together with holders of common stock, subject to a beneficial ownership blocker of either 4.99% or 9.99%, as elected by each holder. The shares of Series A Preferred Stock are convertible into common stock at a conversion price of $6.30 per share.

Series B Convertible Preferred Stock and Warrants

On July 21, 2025, the Company entered into the July 2025 Purchase Agreement with certain accredited investors, pursuant to which the Company agreed to issue and sell, in a private placement, (i)1,000,000 Series B Shares convertible into 100,000,000 shares of Common Stock, (ii) Release Date Warrants to purchase up to 500,000 shares of Series B Preferred Stock, and (iii) Enrollment Date Warrants to purchase up to 1,000,000 shares of Series B Preferred Stock. The closing of the Series B Offering occurred on July 22, 2025.

The aggregate gross proceeds to the Company from the issuance and sale of the Series B Shares, Release Date Warrants, and Enrollment Date Warrants was $175 million, before deducting fees to be paid to the placement agents and financial advisors of the Company and other estimated offering expenses payable by the Company. The Company incurred $11.1 million in offering costs resulting in net proceeds of $163.9 million. The aggregate exercise price of the Warrants is approximately $284 million.

The Release Date Warrants and Enrollment Date Warrants were initially recorded at fair value of $152.7 million as these instruments were considered to be liability classified at issuance because the underlying preferred shares were redeemable, requiring the Company to settle the instruments in cash under certain conditions. The remaining gross proceeds of $22.3 million was allocated to the Series B Preferred Stock. The Company allocated the offering costs to each of the instruments utilizing the relative fair value method. As a result, total offering costs of $11.1 million were allocated, with $4.9 million allocated to the warrants and expensed in the period ending September 30, 2025 and $6.2 million allocated to the Series B Preferred Stock and treated as a reduction in proceeds.

At the Company’s special meeting of stockholders held on September 26, 2025 (the “2025 Special Meeting”), the stockholders approved, among other things, the issuance of all shares of Common Stock issuable upon conversion of the Series B Preferred Stock. Following such approval, the Series B Preferred Stock automatically converted into the Conversion Shares subject to a conversion cap that limits the conversion of the Series B Preferred Stock such that a holder may not beneficially own more than 4.99% of the shares of Common Stock that would be issued and outstanding following such conversion. This resulted in 361,442 shares of Series B Preferred Stock converting into 36,144,200 shares of Common Stock.

The Series B Preferred Stock is entitled to receive dividends on an as-converted-to-common-stock basis when and if declared by the Board of Directors and converts to common stock at a ratio of one-for-one hundred, subject to certain potential adjustments. From the date of issuance until the requisite approval, the Series B Preferred Shares contained a redemption right that was outside of the Company’s control. Following the requisite approval, there is no liquidation preference or redemption rights and the shares are considered to be equity classified. After Requisite Approval at the option of the holder they can convert the Series B Preferred Stock shares to shares of the Company’s Common Stock subject to certain ownership limitations. Following stockholder approval, each share of Series B Preferred Stock, is convertible into Conversion Shares at a conversion price of $1.75 per share. For the three months ended March 31, 2026 there were 67,679 shares of Series B Preferred stock converted into 6,767,900 shares of common stock.

The Release Date and Enrollment Date Warrants provide for the purchase of up to 500,000 and 1,000,000 shares of Series B Preferred Stock, respectively. The Release Date Warrants and Enrollment Date Warrants have an exercise price of $218.75 and $175.00 per share, respectively. The Release Date Warrants have an expiration of the earlier of five years from the issuance date or the Phase II Release Date (as defined in the warrant). The Enrollment Warrants have an expiration date of the earlier of five years from the issuance date or the Phase II Enrollment Date (as defined in the warrant). There were 17,000 Enrollment Warrants exercised for 17,000 shares of Series B Preferred Stock during thethree months ended March 31, 2026.

The Release Date and Enrollment Date Warrants were initially classified as liabilities because the underlying preferred shares were redeemable, requiring the Company to settle the instruments in cash under certain conditions. Upon receiving the requisite approval on September 26, 2025, the preferred stock was no longer redeemable, and the Release Date Warrants and Enrollment Date Warrants were reclassified from liabilities to stockholders’ equity.

March 2026 Public Offering

On March 17, 2026, the Company entered into an underwriting agreement (the “March 2026 Public Offering”) under which the Company agreed to issue and sell (i)19,324,677 shares of the Company's common stock, par value $0.0001 per share (the "Firm Shares"), at a public offering price of $3.85 per share, and (ii) pre-funded warrants to purchase up to 2,753,246 shares of common stock (the “Pre-Funded Warrants”), at a public offering price of $3.8499 per Pre-Funded Warrant, which represents the per share public offering price for the Firm Shares less the $0.0001 per share exercise price of each Pre-Funded Warrant. The Company also granted the underwriters a 30-day option to purchase up to an additional 3,311,688 shares of common stock at the public offering price, less underwriting discounts and commissions (the “Optional Shares”). As of March 31, 2026, the underwriters partially exercised their option and purchased an additional 2,000,000 shares of common stock at the public offering price of $3.85 per share.

The Company received aggregate net proceeds from the offering, including the partial exercise of the underwriters’ option, of approximately $86.4 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. Issuance costs were allocated between the common stock and the pre-funded warrants on a relative fair value basis and charged to additional paid-in capital.

Earnout Shares

On October 22, 2021 (the “Closing Date”), the Company consummated the business combination (the “Business Combination”) contemplated by the agreement and plan of merger, dated as of June 21, 2021, as amended on August 12, 2021, made by and among Big Cypress Acquisition Corp., a Delaware corporation (“BCYP”), Big Cypress Merger Sub Inc., a Delaware corporation (“Merger Sub”), the Company, and Shareholder Representative Services LLC, a Colorado limited liability company, solely in its capacity as the representative, agent and attorney-in-fact of the SAB Stockholders (the “Business Combination Agreement ”). Upon closing of the Business Combination, Merger Sub merged with SAB Biotherapeutics, with SAB Biotherapeutics as the surviving company of the merger. Upon closing of the Business Combination, BCYP changed its name to “SAB Biotherapeutics, Inc.”

Additionally, the Business Combination Agreement included an earnout provision whereby the shareholders of SAB Biotherapeutics shall be entitled to receive additional consideration (“Earnout Shares”) if the Company meets certain Volume Weighted Average Price (“VWAP”) thresholds, or a change in control with a per share price exceeding the VWAP thresholds within a five-year period immediately following the Closing.

The Earnout Shares shall be released in four equal increments as follows:

(i)

25% of the Earnout Shares shall be released if, at any time during the five (5)-year period immediately following the Closing Date, the VWAP of the Company’s publicly traded common stock is greater than or equal to $150.00 for any twenty (20) trading days within a period of thirty (30) consecutive trading days (the “First Earnout”).

(ii)

25% of the Earnout Shares shall be released if, at any time during the five (5)-year period immediately following the Closing Date, the VWAP of the Company’s publicly traded common stock is greater than or equal to $200.00 for any twenty (20) trading days within a period of thirty (30) consecutive trading days (the “Second Earnout”).

(iii)

25% of the Earnout Shares shall be released if, at any time during the five (5)-year period immediately following the Closing Date, the VWAP of the Company’s publicly traded common stock is greater than or equal to $250.00 for any twenty (20) trading days within a period of thirty (30) consecutive trading days (the “Third Earnout”).

(iv)

25% of the Earnout Shares shall be released if, at any time during the five (5)-year period immediately following the Closing Date, the VWAP of the Company’s publicly traded common stock is greater than or equal to $300.00 for any twenty (20) trading days within a period of thirty (30) consecutive trading days (the “Fourth Earnout” and together with the First Earnout, the Second Earnout and the Third Earnout, the “Earnouts”).

Pursuant to the terms of the Business Combination Agreement, SAB Biotherapeutics’ securityholders (including vested option holders) who own SAB Biotherapeutics securities immediately prior to the Closing Date will have the contingent right to receive their pro rata portion of (i) an aggregate of 1,200,000 Earnout Shares, of which 150,806 are contingently issuable based upon future satisfaction of the aforementioned VWAP thresholds. The remaining 1,049,194 are legally issued and outstanding, if the Company does not meet the above VWAP thresholds, or a change in control with a per share price below the VWAP thresholds occurs within a five-year period immediately following the Closing Date, the 1,049,194 shares will be returned to the Company.

The Earnout Shares are indexed to the Company’s equity and meet the criteria for equity classification. On the Closing Date, the fair value of the 1,200,000 Earnout Shares was $101.3 million. The Company recorded the Earnout Shares as a stock dividend by reducing additional paid-in capital, which was offset by the increase in additional paid-in capital associated with the Business Combination.

Shelf Registration Statement

On December 29, 2025 the Company filed a Registration Statement on Form S-3 (Registration No. 333-292482) (the “Shelf Registration Statement”), declared effective on January 7, 2026 by the SEC, which includes a base prospectus that allows the Company to offer and sell, from time to time, in one or more offerings, common stock, preferred stock, debt securities, warrants, rights or units up to an aggregate public offering price of $300 million. The Shelf Registration Statement is intended to preserve the Company’s flexibility to raise capital from time to time, if and when needed.

(9) Stock Option Plans

On August 5, 2014, the Company approved a stock option grant plan (the “2014 Equity Incentive Plan”) for employees, directors, and non-employee consultants, which provides for the issuance of options to purchase common stock. As of March 31, 2026, there were 728,650 shares of common stock reserved for issuance under the 2014 Equity Incentive Plan, with 534,290 shares of common stock available for grant and 194,360 shares of common stock underlying outstanding grants.

The Company adopted the 2021 Omnibus Equity Incentive Plan (as amended, the “2021 Equity Incentive Plan”, and collectively with the 2014 Equity Incentive Plan, the “Equity Compensation Plans”), which reserved 1,100,000 shares of common stock for issuance. At the beginning of each calendar year, the shares reserved for future issuance shall increase by two percent (2%) of the total number of shares of common stock issued and outstanding on a fully-diluted basis as of the end of the Company’s immediately preceding fiscal year (or such lesser number of shares, including no shares, determined by the Board in its sole discretion); provided, however, that the aggregate number of additional shares available for issuance pursuant to this paragraph (b) shall not exceed a total of 500,000 shares (the “Annual Increase”). In June 2024, the Company held the 2024 Annual Meeting of Stockholders (the “2024 Annual Meeting”). At the 2024 Annual Meeting, the stockholders of the Company approved an amendment to the 2021 Equity Incentive Plan which, among other things, increased the number of shares of common stock available for grant under the 2021 Equity Incentive Plan by 3,900,000 and increased the Annual Increase from 2% to 5% (the “2021 Plan Amendment”). At the 2025 Special Meeting, the stockholders of the Company approved an amendment to the 2021 Equity Incentive Plan which, among other things, increased the number of shares of common stock available for grant under the 2021 Equity Incentive Plan by 24,180,000 and increased the maximum number of additional shares available pursuant to the Annual Increase from 10,000,000 shares to 73,750,000 shares. As of March 31, 2026, there were 47,624,055 shares of common stock reserved for issuance under the 2021 Equity Incentive Plan, with 8,848,019 shares of common stock available for grant and 38,776,036 shares of common stock underlying outstanding grants.

The Company offers an Employee Stock Purchase Plan (“ESPP”) that allows eligible employees to purchase shares of common stock at a discount of up to 15% from the lower of the fair market value at the beginning or end of the offering period. Under ASC 718, the ESPP is classified as compensatory, and stock-based compensation expense is recognized for the fair value of the discount and any embedded option features. No shares were issued under the ESPP during either thethree months ended March 31, 2026 and 2025, andno stock-based compensation expense was recognized. As of March 31, 2026,100,000 shares remained available for future issuance.

The expected term of the stock options was estimated using the “simplified” method, as defined by the SEC’s Staff Accounting Bulletin No. 107, Share-Based Payment. The volatility assumption was determined by examining the historical volatilities for industry peer companies, as the Company does not have sufficient trading history for its common stock. The risk-free interest rate assumption is based on the U.S. Treasury instruments whose term was consistent with the expected term of the options. The dividend assumption is based on the Company’s history and expectation of dividend payouts. The Company has never paid dividends on its common stock and does not anticipate paying dividends on its common stock in the foreseeable future. Therefore, the Company has assumed no dividend yield for purposes of estimating the fair value of the options.

Stock Options

Stock option activity for employees and non-employees under the Equity Compensation Plans for thethree months ended March 31, 2026, was as follows:

Total unrecognized compensation cost related to non-vested stock options as of March 31, 2026, was approximately$97.4 million and is expected to be recognized within future operating results over a weighted-average period of 3.53 years.

The weighted average grant date fair value of options granted during the three months ended March 31, 2026, was$3.61 per share. During the three months ended March 31, 2026,150,849 options vested with a fair value totaling$0.5 million.

There were no stock options granted during the three months ended March 31, 2025. During the three months ended March 31, 2025,281,812 options vested with a fair value totaling$1.1 million.

The estimated fair value of stock options granted to employees and consultants during thethree months ended March 31, 2026 and 2025, were calculated using the Black-Scholes option-pricing model using the following assumptions:

*No options were granted during the three months ended March 31, 2025.

Restricted Stock

Stock award activity for employees and non-employees under the Equity Compensation Plans for thethree months ended March 31, 2026, was as follows:

At March 31, 2026, the Company had an aggregate of$0.1 million of unrecognized equity-based compensation related to restricted stock units (“RSUs”) outstanding. During the three months ended March 31, 2026, a total of 4,180 RSUs vested. The aggregate fair value of RSUs vested during the three-month period was approximately$48 thousand. Of the 4,180 RSUs issued,1,163 units were withheld and returned to the Company in satisfaction of employee payroll withholding tax obligations. For the three months ended March 31, 2026, the Company issued a net total of 3,017 RSUs. The unrecognized expense for restricted stock units is expected to be recognized within future operating results over a weighted average period of 0.76 years.

Stock-based compensation expense

Stock-based compensation expense for thethree months ended March 31, 2026 and 2025, was as follows:

(10) Warrants

Public Warrants

Each whole Public Warrant entitles the holder to purchaseone share of the Company's common stock at a price of $115.00 per share, subject to adjustment as discussed herein.

Once the warrants become exercisable, the Company may call the warrants for redemption:

•

in whole and not in part;

•

at a price of $0.01 per warrant;

•

upon not less than 30 days’ prior written notice of redemption (the “30-day redemption period”) to each warrant holder; and if, and only if, the reported last sale price of the common stock equals or exceeds $180.00 per share (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) for any 20 trading days within a 30-trading day period ending three business days before the Company sends the notice of redemption to the warrant holders.

If the Company calls the warrants for redemption as described above, management will have the option to require any holder that wishes to exercise its warrant to do so on a “cashless basis.” If management takes advantage of this option, all holders of warrants would pay the exercise price by surrendering their warrants for that number of shares of common stock equal to the quotient obtained by dividing (x) the product of the number of shares of common stock underlying the warrants, multiplied by the excess of the “fair market value” (defined below) over the exercise price of the warrants by (y) the fair market value. The “fair market value” shall mean the average reported last sale price of the common stock for the 10 trading days ending on the third trading day prior to the date on which the notice of redemption is sent to the holders of warrants.

Each warrant will expire on the fifth anniversary of the Business Combination, which occurred on October 22, 2021. As a result, all outstanding warrants will expire on October 22, 2026, unless earlier exercised or redeemed in accordance with their terms. Once expired, the warrants will have no further value and will no longer be exercisable.

Private Placement Warrants

The Private Placement Warrants and the common stock issuable upon the exercise of the Private Placement Warrants were not transferable, assignable or saleable until after the completion of the Company's merger transaction in 2021. Additionally, the Private Placement Warrants are exercisable on a cashless basis and will be non-redeemable as long as they are held by the initial purchasers or their permitted transferees. If the Private Placement Warrants are held by someone other than the initial purchasers or their permitted transferees, the Private Placement Warrants will be redeemable by the Company and exercisable by such holders on the same basis as the Public Warrants.

Each warrant will expire on the fifth anniversary of the Business Combination, which occurred on October 22, 2021. As a result, all outstanding warrants will expire on October 22, 2026, unless earlier exercised or redeemed in accordance with their terms. Once expired, the warrants will have no further value and will no longer be exercisable.

PIPE Warrants and PIPE Placement Agent Warrants

In December 2022, the Company entered into a securities purchase agreement with certain institutional and accredited investors for the sale by the Company of 736,337 shares of common stock and the PIPE Warrants to purchase up to 736,337 shares of common stock, in a private placement offering. The combined purchase price of each share and accompanying PIPE Warrant was $10.80 (the “December 2022 Private Placement”). Three directors of the Company participated in the December 2022 Private Placement, each paying a $1.25 premium per share and accompanying PIPE Warrant. The PIPE Warrants, including those purchased by the participating directors of the Company, are exercisable at an exercise price equal to $10.80 per share, and are exercisable forfive years from the date of issuance. The Company received gross proceeds of approximately $8.0 million before deducting transaction related fees and expenses. The Company paid Brookline Capital Markets, the placement agent, a cash fee equal toseven percent of the gross proceeds received by the Company in the December 2022 Private Placement. The Company also issued Brookline Capital Markets the PIPE Placement Agent Warrants to purchase up to an aggregate of 21,091 shares of common stock, equal to 7% of the number of shares purchased by investors introduced to the Company by Brookline Capital Markets. The PIPE Placement Agent Warrants have an exercise price equal to $13.50 per share and are exercisable six months from the date of issuance and expire five years from the date of issuance.

2023 Ladenburg Agreement Warrants

On March 21, 2023, the Company entered into a settlement agreement with Ladenburg Thalmann & Co. Inc. (“Ladenburg”), effective March 23, 2023 (the “2023 Ladenburg Agreement”, regarding the action brought by Ladenburg, the “Ladenburg Action”). In connection with the 2023 Ladenburg Agreement, on March 24, 2023, the Company (i) issued the Ladenburg Warrants to purchase up to 30,000 shares of common stock, exercisable forthree years from the date of issuance at $5.424 per share; and (ii) furnished to Ladenburg a one-time cash payment of $500 thousand. Pursuant to the terms and subject to the conditions set forth in the 2023 Ladenburg Agreement, the Company will (i) no later than June 30, 2023, pay $1.5 million to Ladenburg in cash or shares of common stock, at the Company’s option; and (ii) no later than December 31, 2023, pay $1.1 million to Ladenburg in cash or shares of common stock, at the Company’s option. Following the completion of the Company’s obligations under the 2023 Ladenburg Agreement, Ladenburg has agreed to dismiss the Ladenburg Action with prejudice and extinguish any and all obligations of the Company in connection therewith. On June 30, 2023, in accord with the terms of the agreement, the Company issued 191,689 sharesof common stockto satisfy a portion of its obligations under the 2023 Ladenburg Agreement. Following the completion of the 2023 Private Placement, the Company settled the remaining $1.1 million due to Ladenburg in cash.

September 2023 Purchase Agreement Warrants

As of March 31, 2026, the Company had outstanding 107,115 Preferred Tranche C Warrants to purchase shares of Series A-3 Preferred Stock having an aggregate exercise price of approximately $107.1 million.

The Preferred Tranche C Warrants were classified as derivative liabilities because they are redeemable for cash upon occurrence of a Fundamental Transaction, (as defined in the Forms for such warrants), which may be outside the control of the Company.

For more information see Note 8, Stockholders’ Equity.

Preferred PIPE Placement Agent Warrant

On November 21, 2023, the Company issued to Chardan Capital Markets LLC, the placement agent for the September 2023 Offering, a warrant to purchase 850,119 shares (as adjusted following the Reverse Stock Split) of the Company’s common stock (“the Preferred PIPE Placement Agent Warrants”). The Preferred PIPE Placement Agent Warrants have an exercise price equal to $6.30 per share (subject to adjustment for stock dividends and splits) and are exercisable in whole or in part, at any time or times on or after the issuance date and on or before October 2, 2028. The Preferred PIPE Placement Agent Warrant was classified in equity in additional paid-in capital.

Preferred PIPE Series B Warrants

On July 21, 2025, the Company issued the Release Date Warrants and Enrollment Date Warrants to various investors as part of the Series B Offering. The Release Date Warrants and Enrollment Date Warrants provide for the purchase of up to 500,000 and 1,000,000 shares of Series B Preferred Stock, respectively. The Release Date Warrants and Enrollment Date warrants have an exercise price of $218.75 and $175.00 per share, respectively. The Release Date Warrants have an expiration of the earlier offive years from the issuance date or the Phase II Release Date. The Enrollment Warrants have an expiration date of the earlier offive years from the issuance date or the Phase II Enrollment Date.

The Release Date Warrants and Enrollment Date Warrants were initially classified as liabilities because the underlying preferred shares were redeemable, requiring the Company to settle the instruments in cash under certain conditions; however, upon receiving the requisite approval on September 26, 2025, the preferred stock was no longer redeemable, and the Release Date Warrants and Enrollment Date Warrants were reclassified from liabilities to stockholders’ equity. There were 17,000 Enrollment Warrants exercised during thethree months ended March 31, 2026.

Pre-Funded Warrants

In March 2026, the Company issued pre‑funded warrants to purchase up to 2,753,246 shares of common stock at a public offering price of $3.8499 per warrant, which represents the public offering price of $3.85 per share of common stock less the $0.0001 exercise price per share. The pre-funded warrants are indexed to the Company’s common stock and meet all other conditions for equity classification. The pre-funded warrants were classified as equity and accounted for as a component of additional-paid-in capital at the time of issuance.

The following table summarizes warrant activity for thethree months ended March 31, 2026 and 2025:

(1)

On January 1, 2025,42,846 Preferred Tranche B Warrants expired, unexercised. The Company recognized a gain of $3 thousand in other income in our condensed consolidated statement of operations, representing the fair value of the warrants at expiration. The valuation as of December 31, 2024, was based on a risk-free interest rate of 3.93%, an expected remaining term of 0.23 periods, implied volatility of 75%, and an underlying stock price of $309.37.

Presentation and Valuation of the Warrants

Liability Classified Warrants

Public Warrants and Private Placement Warrants

The Public Warrants and Private Placement Warrants are accounted for as liabilities in accordance with ASC 815-40, Derivatives and Hedging—Contracts in Entity’s Own Equity and were presented within warrant liabilities on the condensed consolidated balance sheets as of March 31, 2026 and December 31, 2025. The initial fair value of the warrant liabilities was measured at fair value at the Closing Date, and changes in the fair value of the warrant liabilities were presented within changes in fair value of warrant liabilities in the condensed consolidated statements of operations and comprehensive loss for three months ended March 31, 2026 and 2025.

On the Closing Date, the Company established the fair value of the Private Placement Warrants utilizing both the Black-Scholes Merton formula and a Monte Carlo Simulation (the “MCS”) analysis. Specifically, the Company considered an MCS to derive the implied volatility in the publicly-listed price of the Public Warrants. The Company then considered this implied volatility in selecting the volatility for the application of a Black-Scholes Merton model for the Private Placement Warrants. The Company determined the fair value of the Public Warrants by reference to the quoted market price.

The Public Warrants were classified as a Level 1 fair value measurement, due to the use of the quoted market price, and the Private Placement Warrants held privately by assignees of Big Cypress Holdings LLC, were classified as a Level 3 fair value measurement, due to the use of unobservable inputs. See Note 11, Fair Value Measurements, for changes in fair value of the Private Placement Warrants.

The key inputs into the valuations as of March 31, 2026 and December 31, 2025, were as follows:

Series APreferred Warrants

Should the Company enter into or be party to a fundamental transaction, the Company will be required to purchase all outstanding Warrants from the holders by paying cash in an amount equal to the Black Scholes Value of the unexercised portion of each Series A Preferred Warrant. As a result, the Series A Preferred Warrants are accounted for as derivative liabilities in accordance with ASC 480 and ASC 815-40, Derivatives and Hedging—Contracts in Entity’s Own Equity and were presented within warrant liabilities on the condensed consolidated balance sheets as of March 31, 2026 and December 31, 2025. The initial fair value of the warrant liabilities was measured at fair value at the Closing Date, and changes in the fair value of the warrant liabilities were presented within changes in fair value of warrant liabilities in the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2026 and 2025.

The Company established the fair value of the Preferred Warrants utilizing the Black-Scholes Merton formula.

All tranches of the Preferred Warrants were classified as Level 3 fair value measurements, due to the use of unobservable inputs. See Note 11, Fair Value Measurements, for changes in fair value of the Preferred Warrants.

The key inputs utilized in determining the fair value of each Preferred Tranche C Warrant as of March 31, 2026 and December 31, 2025, were as follows:

(1)

Reflects a probability-weighted input derived from multiple Black-Scholes calculations. These calculations incorporate the Company’s estimated probability of dissolution, should SABS’ intellectual property fail to yield positive results in forthcoming clinical trials, potentially leading to dissolution before 2028. The probability was 47.5% as of March 31, 2026 and December 31, 2025.

(11) Fair Value Measurements

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The following fair value hierarchy classifies the inputs to valuation techniques that would be used to measure fair value into one of three levels:

Level 1: Unadjusted quoted prices in active markets for identical assets or liabilities.

Level 2: Inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active.

Level 3: Unobservable inputs that reflect the reporting entity’s own assumptions.

The following tables present information about the Company's assets and liabilities that are measured at fair value on a recurring basis at March 31, 2026 and December 31, 2025, and indicate the fair value hierarchy of the valuation inputs the Company utilized to determine such fair value:

The following table provides a summary of the changes in Level 3 fair value measurements for the Private Placement Warrant liability:

The following table provides a summary of the changes in Level 3 fair value measurements for the Preferred Warrant liabilities:

As of March 31, 2026 and December 31, 2025, the Company didnot have any other assets or liabilities that are recorded at fair value on a recurring basis.

The Company believes that the carrying amounts of its cash and cash equivalents, accrued interest receivable, notes payable, accounts payable, accrued expenses and other current liabilities approximate their fair values due to their near-term maturities.

(12) Investments

Available-For-Sale Debt Securities

At March 31, 2026, the fair value and amortized cost of the Company’s available-for-sale debt securities, summarized by type of security, consisted of the following:

At December 31, 2025, the fair value and amortized cost of the Company’s available-for-sale debt securities, summarized by type of security, consisted of the following:

The amortized cost and estimated fair value by maturity or next repricing date of investment securities at March 31, 2026 are shown in the following table. Fixed rate securities are classified according to their contractual maturities without consideration of principal amortization, potential prepayments or call options. Accordingly, actual maturities may differ from contractual maturities.

The following table shows gross unrealized losses and fair values of available-for-sale securities for which an allowance for credit losses has not been recorded, aggregated by investment category and length of time that individual securities have been in a continuous loss position as of March 31, 2026:

The following table shows gross unrealized losses and fair values of available-for-sale securities for which an allowance for credit losses has not been recorded, aggregated by investment category and length of time that individual securities have been in a continuous loss position as of December 31, 2025:

The unrealized losses on the Company’s available-for-sale debt securities as of March 31, 2026 and December 31, 2025 were caused by fluctuations in market value and interest rates as a result of the economic environment. The Company concluded that an allowance for credit losses was unnecessary as of March 31, 2026 and December 31, 2025 because the decline in the market value was attributable to changes in market conditions and not credit quality, and that it is neither management’s intention to sell nor is it more likely than not that the Company will be required to sell these investments prior to recovery.

Gross realized gains and losses on the sale of short-term and long-term investments are included in other income in the Company’s condensed consolidated statements of operations and comprehensive loss. Net realized gains for the three months ended March 31, 2026, include $47 thousand reclassified from accumulated comprehensive income (loss), representing unrealized gains previously recognized in other comprehensive income that were realized upon the sale of available-for-sale debt securities. The following table summarizes the Company’s gross realized gains and losses on the sale of available-for-sale debt securities:

Accrued interest receivable related to the above investment securities was$1.6 million and$0.9 million at March 31, 2026 and December 31, 2025, respectively, and is included within accrued interest receivable on the condensed consolidated balance sheets.

Equity Securities

The Company holds investments in mutual funds that are classified as equity securities, primarily representing diversified portfolios of publicly traded equity instruments managed by third-party investment advisors. As of March 31, 2026 and December 31, 2025, the Company had$11.4 million and$59.1 million, respectively, of equity securities included within short-term investments on the condensed consolidated balance sheets. The following is a summary of unrealized and realized gains (losses) recognized on equity securities included in other income (expense) in the condensed consolidated statements of operations and comprehensive loss.

(13) Income Taxes

Due to current and prior year losses the Company does not expect to have any Income Tax Provision.

The Company continues to record a valuation allowance on its net deferred tax assets. The valuation increased by approximately $4.0 million during thethree months ended March 31, 2026. The Company has not recognized any reserves for uncertain tax positions.

(14) Employee Benefit Plan

The Company sponsors a defined contribution retirement plan. All the Company’s employees are eligible to be enrolled in the employer-sponsored contributory retirement savings plan, which include features under Section 401(k) of the Internal Revenue Code of 1986, as amended, and provides for Company matching contributions. The Company’s contributions to the plan are determined by its Board of Directors, subject to certain minimum requirements specified in the plan. The Company has historically made matching contributions of 100% on 3% of the employee contributions, with an additional 50% match on the next 2% of employee contributions. The Company made contributions of approximately$0.2 million during the three months ended March 31, 2026, and$0.1 million, during the three months ended March 31, 2025.

(15) Commitments and Contingencies

The Company is not a party to any litigation, and, to its best knowledge, no action, suit, or proceeding has been threatened against the Company which are expected to have a material adverse effect on its financial condition, results of operations or liquidity.

Fortrea Inc.

In October 2024, the Company entered into a clinical master services agreement and work orders with Fortrea Holdings Inc. (“Fortrea”) to act as the contract research organization (“CRO”) overseeing the Company’s Phase 2b efficacy and safety study for SAB-142. Approximately $2.4 million and $0.8 million was expensed with respect to the Fortrea agreements during the period ended March 31, 2026 and 2025, respectively, which amounts are included in research and development expenses in the accompanying consolidated statements of operations and comprehensive loss. The Company expects to make ongoing payments to Fortrea over the next 12 to 18 months in connection with services provided by Fortrea, as well as clinical trial site and other pass-through costs relating to the Phase 2b efficacy and safety study for SAB-142.

(16) Segment Reporting

Operating segments are defined as components of the entity for which separate financial information is made available and that is regularly evaluated by the chief operating decision maker (CODM) in making decisions regarding resource allocation and assessing performance. The Company's CODM is its chief executive officer and the Company manages its operations as asingle segment for the purposes of assessing performance and making operating decisions. The Company is focused on the development of a human anti-thymocyte globulin focused on preventing or delaying the progression of T1D.

The CODM assesses the Company's performance by reviewing GAAP operating expense and significant expenses by function along with the annual budget. The chief operating decision maker considers budget-to-actual variances on a quarterly basis when making decisions about the allocation of operating and capital resources.

The following table is representative of the significant expense categories regularly provided to the CODM when managing the Company's single reporting segment. A reconciliation to condensed consolidated operating expenses as oursingle segment operating loss for thethree months ended March 31, 2026 and 2025, is included in the table below:

The measure of segment assets is reported on the Condensed Consolidated Balance Sheets as Cash and cash equivalents and Short-term and Long-term investments.

Long-lived assets are reported on the Condensed Consolidated Balance Sheets as Property, plant and equipment, net of accumulated depreciation and these assets are held in the U.S.

(17) Subsequent Events

Exercise of Underwriters’ Option

In April 2026, in connection with the March 2026 Public Offering, the underwriters partially exercised their option to purchase an additional 610,188 shares of common stock at the public offering price of $3.85 per share, less underwriting discounts and commissions, resulting in additional net proceeds to the Company of approximately $2.2 million. As of April 20, 2026, the remaining Optional Shares of 701,500 expired without exercise.

Manufacturing Services Agreement

On April 28, 2026 (the “MSA Effective Date”), the Company entered into a Master Manufacturing Services Agreement (the “MSA”) with Emergent BioSolutions Canada Inc. (“Emergent”). Pursuant to the MSA, Emergent will perform clinical and commercial manufacturing and related services for the Company with respect to SAB-142 (the “Product”) at Emergent’s facility in Canada. The MSA commences on the MSA Effective Date and would continue for a period of five (5) years from the date the Product obtains approval from the United States Food and Drug Administration (“FDA”), with a minimum aggregate spend following any FDA approval equal to $36 million. The parties may mutually agree to extend the term by execution of an amendment at any time prior to its expiration. The MSA may be terminated: (i) by either party immediately upon an insolvency or bankruptcy event; (ii) by Emergent immediately if the Company fails to pay undisputed amounts within thirty (30) days after written notice; (iii) by either party for material breach, subject to a cure period of thirty (30) days (or up to ninety (90) days if diligently pursued); (iv) by mutual written agreement; or (v) by either party upon thirty (30) days’ notice if a force majeure event prevents performance for ninety (90) consecutive calendar days. Upon termination by Emergent for the Company’s insolvency, non-payment, or material breach, the Company must pay Emergent an amount equal to the minimum annual aggregate spend for each remaining calendar year of the term, less saved costs. The applicable batch price and fees for commercial manufacturing services will be agreed upon in a subsequent amendment to the MSA. Development services pricing will be set forth in individual statements of work executed by the parties. Pricing is subject to annual adjustments. Emergent has the sole and exclusive right to manufacture the Product during the term of the MSA. The Company may contract with a third party to establish an alternative manufacturing source. The Company may purchase from an alternative source in limited circumstances and in all cases, only in quantities that Emergent is unable or declines to manufacture. The MSA includes customary mutual confidentiality obligations.

Sanford Lease Amendment

On April 1, 2026, the Company entered into a lease amendment for its operating lease with Sanford Health, which reduced the lease square footage to 13,492 and decreased the monthly lease payments to approximately $33 thousand.