DEEP FISSION, INC.

Note 1: Description of Business and Basis of Presentation

Organization

Deep Fission, Inc. (“Deep Fission” or the “Company”) was incorporated on July 17, 2023, under the laws of the state of Delaware.

Surfside Acquisition Inc. (“Surfside”) was incorporated in the State of Delaware on December 10, 2021. Prior to the Merger (as defined below), Surfside was a “shell company” (as defined in Rule 12b-2 under Securities Exchange Act of 1934, as amended (the “Exchange Act”)). On September 5, 2025, Surfside completed a merger (the “Merger”) with Deep Fission Nuclear, Inc. (formerly known as Deep Fission, Inc.), a private Delaware corporation (“Legacy Deep Fission”), pursuant to an Agreement and Plan of Merger and Reorganization (the “Merger Agreement”), under which a wholly owned subsidiary of Surfside merged with and into Legacy Deep Fission, with Legacy Deep Fission continuing as the surviving corporation and becoming a wholly owned subsidiary of Surfside. In connection with the transaction, Surfside changed its name to Deep Fission, Inc. For financial reporting purposes, the transaction was treated as a recapitalization and reverse acquisition, with Legacy Deep Fission considered the accounting acquirer. See below,Recapitalization, for the accounting of the Merger.

Following the consummation of the Merger, the business previously conducted by Legacy Deep Fission became the business conducted by the Company. The Company’s headquarters are located in Berkeley, California.

Operations

The Company is a nuclear energy technology company developing a small modular reactor based on established pressurized water reactor technology, with novel emplacement in deep boreholes approximately one mile below the Earth’s surface. The Company is currently participating in the U.S. Department of Energy (“DOE”) Reactor Pilot Program, and we expect to demonstrate our system as part of the DOE Reactor Pilot Program.

Deep Fission’s current activities include reactor development, geological evaluation, large-diameter borehole drilling research and development, geothermal testing, safety analysis, regulatory engagement, site development, and commercialization planning.

Basis of Presentation

The accompanying consolidated financial statements for the years ended December 31, 2025 and 2024 have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). The consolidated financial statements include the results of the Company and its wholly owned or controlled subsidiary. All intercompany transactions and balances have been eliminated during consolidation.

For accounting purposes, the Merger was treated as a reverse recapitalization outside the scope of ASC 805 (seeOrganization above andRecapitalization below), with Legacy Deep Fission considered the accounting acquirer and the Company (formerly Surfside Acquisition Inc.) considered the legal acquirer. Accordingly, these consolidated financial statements represent a continuation of the financial statements of Legacy Deep Fission, with the Merger reflected as the equivalent of Legacy Deep Fission issuing shares for the net assets of Surfside, accompanied by a recapitalization.

All periods prior to the Merger reflect the historical financial position, results of operations, and cash flows of Legacy Deep Fission. The consolidated financial statements are presented in the name of the legal parent; however, they represent the historical operations of Legacy Deep Fission.

The number of shares and corresponding capital amounts and earnings per share, where applicable, have been retroactively restated to reflect the Common Share Conversion Ratio established in connection with the Merger. No goodwill or other intangible assets were recorded as a result of the transaction.

Liquidity and Going Concern

As of December 31, 2025 and 2024, the Company’s cash and cash equivalents were $23,719,422 and $6,728,895, respectively. The Company continues to incur significant operating losses. For the years ended December 31, 2025 and 2024, the Company had a net loss of $61,002,954 and $5,713,369, respectively, and net cash used in operating activities of $13,051,195 and $2,799,642, respectively. As of December 31, 2025 and 2024, the Company had accumulated deficits of $66,727,099 and $5,724,145, respectively. Management expects that significant on-going operating expenditures will be necessary to successfully implement the Company’s business plan and develop and market its products and services. These circumstances raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that these financial statements are issued. Implementation of the Company’s plans and its ability to continue as a going concern will depend upon the Company’s ability to establish a source of revenue and raise additional capital to fund its operations.

The Company plans to access capital resources through possible public or private equity issuances, debt financings, corporate collaborations, and other means. The Company has historically been able to raise capital through equity and equity-linked instruments, such as Simple Agreements for Future Equity (“SAFE Notes”) and private placement equity issuances, although no assurance can be provided that it will continue to be successful in raising capital in the future. While the Company believes that it has a reasonable basis for its expectation that it will be able to raise additional funds, there is no assurance that the Company will be able to complete additional financing in a timely manner.

The financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that might be necessary if the Company is unable to continue as a going concern due to the inability to obtain adequate financing in the future.

Recapitalization

As described above, Legacy Deep Fission continued as the surviving corporation and became the Company’s wholly owned subsidiary following the Merger. The Merger was accounted for as a reverse recapitalization and Legacy Deep Fission was considered the accounting acquirer for financial reporting purposes. This determination was based on the facts that, immediately following the Merger:

At the effective time of the Merger, each outstanding share of Legacy Deep Fission capital stock (after giving effect to the conversion of all SAFE Notes of Legacy Deep Fission into shares of Legacy Deep Fission common stock) was converted into the right to receive 17.32141 shares of the Company’s common stock, rounded to the nearest whole share (“Common Share Conversion Ratio”). Accordingly, all share and per share amounts for all periods presented in the accompanying consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect the Common Share Conversion Ratio. There was no effect on the number of shares of common stock or preferred stock authorized for issuance under the Company’s amended and restated certificate of incorporation or the par value of such securities. On September 5, 2025, we issued 85,000 shares of our common stock to an accredited investor (the “Advisor”) in consideration for services rendered in connection with the Merger.

On September 5, 2025, the Company issued an aggregate of 10,000,000 shares of its common stock at a purchase price of $3.00 per share in a private placement (the “Private Placement”) to certain accredited and institutional investors for aggregate gross consideration of $30.0 million. The Company also issued warrants issued to each of the U.S. registered broker-dealers acting as placement agents in connection with the Private Placement representing the right to acquire, on the terms set forth therein,586,666 shares of its common stock.

**Note 2:**Restatement of Previously Issued Consolidated Financial Statements

In connection with the preparation of the Company’s consolidated financial statements as of and for the fiscal year ended December 31, 2025, the Company discovered errors relating to certain inputs and assumptions used in the valuation models for the Company’s SAFE Notes and stock-based compensation expense, which were used to record the fair value of the SAFE Notes and stock-based compensation expense for various equity agreements. The errors resulted in an overstatement of the fair value of SAFE Notes and an understatement of stock-based compensation expense.

As previously announced in the Company’s Current Report on Form 8-K filed with the SEC on April 9, 2026, on April 9, 2026, the Audit Committee of the Company’s board of directors, in consultation with management, concluded that the audited consolidated financial statements for the fiscal year ended December 31, 2024 and for the period from July 17, 2023 (inception) through December 31, 2023, and the unaudited condensed consolidated financial statements for the six month periods ended June 30, 2024 and 2025, and the three- and nine-month periods ended September 30, 2024 and 2025 of the Company could no longer be relied upon as a result of the misstatement.

Furthermore, the misstatement was evaluated under both rollover and iron curtain methods in accordance with ASC 250, and determined to be quantitatively material to certain previously issued financial statements of the Company and as a result, the Company has restated its consolidated financial statements for the periods presented herein. The restatement includes adjustments to SAFE notes, stock-based compensation expense, net loss, and net loss per share.

The misstatement had no material impact on reported cash flows during the period, as the valuations pertained to non-cash transactions.

Although management did not conduct a formal assessment of internal control over financial reporting in accordance with Section 215.02 of the SEC Division of Corporation Finance’s Regulation S-K Corporation Finance Interpretations, as a result of the misstatement and the related restatement, the Company identified material weaknesses in its internal control over financial reporting, which caused its management to conclude that the Company did not maintain effective internal control over financial reporting as of December 31, 2024 and 2025 due to lack of formal controls and standardized procedures related to financial reporting and historical equity accounting processes.

The impacts of the restatement are summarized below:

Consolidated Balance Sheet – As of January 1, 2024

Consolidated Balance Sheet – As of December 31, 2024

Consolidated Statement of Operations – For the year ended December 31, 2024

Consolidated Statement of Stockholders’ Equity (Deficit) for the year ended December 31, 2024

Consolidated Statement of Cash Flows for the year ended December 31, 2024

All referenced amounts for prior period in these financial statements and the notes herein reflect the balances and amounts on a restated basis.

Note 3: Summary of Significant Accounting Policies

The accompanying consolidated financial statements reflect the application of the accounting policies described in this note.

Segments

In accordance with criteria under ASC 280,Segment Reporting, which establishes standards for companies to report in their financial statement information about operating segments, products, services, geographic areas, and major customers, the Company’s chief operating decision maker (“CODM”) has been identified as the Chief Executive Officer. The Company’s CODM reviews results to assess performance, make decisions, and allocate operating and capital resources of the Company as a whole. The CODM has made decisions and assessed performance at the Company level asone segment. The CODM does not distinguish its principal business activities for the purpose of internal reporting and uses net loss, consistent with what is presented in the statement of operations, to allocate resources in the annual budgeting and forecasting process, along with using that measure as a basis for evaluating financial performance quarterly by comparing the actual results with historical budgets.

Use of Estimates

The preparation of the accompanying consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting period. Actual results may differ from these estimates.

Fair Value Measurements

The authoritative guidance with respect to fair value established a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three levels and requires that assets and liabilities carried at fair value be classified and disclosed in one of three categories, as presented below. There areno transfers in and out of Levels 1 and 2, andactivity in Level 3 represents fair value measurements.

Financial instruments measured and reported at fair value are classified and disclosed in one of the following categories:

Level 1 - Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company is able to access.

Level 2 - Valuations based on quoted prices in markets that are not active or for which all significant inputs, other than quoted prices included in Level 1, that are observable either directly or indirectly. These inputs may include (a) quoted prices for similar assets in active markets, (b) quoted prices for identical or similar assets in markets that are not active, (c) inputs other than quoted prices that are observable for the asset, or (d) inputs derived principally from or corroborated by observable market data by correlation or other means.

Level 3 - Valuations based on inputs that are unobservable and significant to the entire fair value measurement.

The Company determines the level in the fair value hierarchy within which each fair value measurement falls in its entirety, based on the lowest level input that is significant to the fair value measurement in its entirety. In determining the appropriate levels, the Company performs an analysis of the assets and liabilities at each reporting period end.

The Company’s cash and cash equivalents, prepaid expenses and other current assets, accounts payable, accrued expenses and other current liabilities approximate their fair value due to the short-term nature of these assets and liabilities. The Company’s SAFE Notes (see Note 6) and RSU liability (see Note 8) were carried at fair value and classified as Level 3 liabilities.

Cash and Cash Equivalents

The Company maintains deposits in financial institutions that at times exceed the insured amounts provided by the Federal Deposit Insurance Corporation (“FDIC”). As of December 31, 2025 and 2024, the amount of cash exceeding the FDIC insurance limit was $23,219,422 and $6,228,584. The Company believes it is not exposed to any significant credit risk to cash. Money market funds and other short-term investments with an original maturity of three months or less are considered cash equivalents.

Property and Equipment

Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Expenditures for repairs and maintenance which do not extend the useful lives of the assets are charged to operations as incurred.

The Company reviews its long-lived assets periodically to determine potential impairment by comparing the carrying value of those assets with the estimated future undiscounted cash flows expected to result from the use of the assets, including cash flows from disposition. Should the sum of the expected future undiscounted cash flows be less than the carrying value, the Company would determine the amount of and recognize an impairment loss at that time in accordance with the guidance. No impairment loss was recognized during the years ended December 31, 2025 and 2024. The estimated useful lives of the Company’s property and equipment are as follows:

SAFE Notes

The Company issued SAFE Notes in exchange for cash financing during the years ended December 31, 2025 and 2024. The Company accounted for its SAFE Notes as derivatives under ASC 815,Derivatives and Hedging, and presented them as long-term liabilities in the accompanying consolidated balance sheets. Changes in the fair value of the SAFE Notes were recorded in earnings.

Immediately upon the effectiveness of the Merger on September 5, 2025, the SAFE Notes were converted into shares of the Company’s common stock (see Note 5).

Research and Development Expenses

Research and development (“R&D”) expenses primarily represent costs incurred to develop the Company’s technology. These costs consist of personnel costs, including salaries, employee benefit costs, bonuses and stock-based compensation expenses, software costs, computing costs, hardware and experimental supplies, and expenses for outside engineering contractors for analytical work and consulting costs. The Company expenses all R&D costs in the periods in which they are incurred.

Stock-Based Compensation

The Company accounts for stock-based compensation in accordance with ASC 718,Compensation - Stock Compensation. The Company classifies awards as either equity-classified or liability-classified based on the terms of the award. Equity-classified awards are measured at the grant-date fair value and recognized as compensation expense over the requisite service period, which is generally the vesting period. Equity-classified awards are not subsequently remeasured. Liability-classified awards are measured at fair value at each reporting date until settlement, with changes in fair value recognized as compensation expense in the period of change. Compensation cost for liability-classified awards is recognized over the requisite service period based on the fair value of the award at each reporting date.

The Company classifies stock-based compensation expense in its statement of operations in the same line items in which the award recipient’s cash and other compensation costs are classified.

Net Loss Per Common Share

The Company calculates basic net loss per common share in accordance with ASC 260,Earnings Per Share, based on the weighted-average number of outstanding common shares during the fiscal period. Diluted loss per common share is based on the weighted-average number of outstanding common shares plus the weighted-average number of potential outstanding common shares. The calculation of diluted net loss does not consider the effect of the warrants to purchase an aggregate of 586,666 common stock with exercise contingent on future events, stock options to purchase an aggregate of 2,325,059 common stock, and unvested RSUs of 669,451, because their inclusion would be anti-dilutive under the treasury stock method. In periods where potentially dilutive securities are anti-dilutive, such amounts are excluded from the calculations of diluted earnings (loss) per share. All potentially dilutive securities are anti-dilutive for the years ended December 31, 2025 and 2024. For the year ended December 31, 2024, the Company had SAFE Notes, the conversion of which would have been anti-dilutive.

Income Tax (Provision) Benefit

The Company accounts for income taxes in accordance with ASC 740,Income Taxes. Deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply in the periods in which those temporary differences are expected to reverse.

The Company evaluates the realizability of its deferred tax assets and establishes a valuation allowance when it is more likely than not that some or all of the deferred tax assets will not be realized. In assessing the need for a valuation allowance, the Company considers all available positive and negative evidence, including historical operating results, future taxable income, and the reversal of existing taxable temporary differences.

The Company recognizes the effect of income tax positions only if those positions are more likely than not to be sustained upon examination by the relevant taxing authorities. The Company recognizes interest and penalties related to uncertain tax positions as a component of income tax expense.

New Accounting Pronouncements

Effective January 1, 2025, the Company adopted ASU 2023-09 “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” which enhances income tax disclosures, including expanded requirements for the rate reconciliation and disaggregation of income taxes paid. The adoption of ASU 2023-09 primarily impacts the presentation and disclosure of income taxes in the Company’s consolidated financial statements beginning in 2025. The adoption did not affect the measurement of the Company’s income tax provision.

In October 2023, the FASB issued ASU 2023-06, “Disclosure Improvements”, to clarify or improve disclosure and presentation requirements of a variety of topics and align the requirements in the FASB ASC with the SEC’s regulations. The amendments in ASU 2023-06 will become effective on the date the related disclosures are removed from Regulation S-X or Regulation S-K by the SEC, and will no longer be effective if the SEC has not removed the applicable disclosure requirement by June 30, 2027. Early adoption is prohibited. Adoption is not expected to have a material impact on the Company’s consolidated financial statements.

In November 2024, the FASB issued ASU 2024-03,’-” Income Statement —Reporting Comprehensive Income —Expense Disaggregation Disclosures” as an update to ASC Topic 220-40, which will be effective for fiscal years beginning after December 15, 2026 and interim periods beginning after December 15, 2027. Early adoption is permitted. ASU 2024-03 was issued to improve the disclosures about a public business entity’s expenses and address requests from investors for more disaggregated disclosures about the types of expenses (including employee compensation, depreciation, and amortization) in commonly presented expense captions (such as general and administrative expenses). In January 2025, the FASB also issued ASU 2025-01 “Income Statement – Reporting Comprehensive Income – Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date” to clarify the effective date provisions of ASU 2024-03 related to expense disaggregation disclosures. The Company is currently evaluating the impact of ASU 2024-03 and ASU 2025-01 on its consolidated financial statements.

In May 2025, the FASB issued ASU 2025-04 “Compensation – Stock Compensation (Topic 718) and Revenue from Contracts with Customers (Topic 606): Clarifications to Share-Based Consideration Payable to a Customer”, which clarifies the accounting for share based consideration payable to a customer, including classification and measurement guidance, to reduce diversity in practice. The amendments are effective for fiscal years, including interim periods, beginning after December 15, 2026, with early adoption permitted. The Company is currently assessing the impact of adopting ASU 2025-04 on its consolidated financial statements but does not expect a material impact.

In December 2025, the FASB issued ASU 2025-11, “Interim Reporting (Topic 270): Narrow Scope Improvements”. The amendments clarify the applicability of the interim reporting guidance in Topic 270, improve the navigability of the interim reporting requirements, and provide a more comprehensive framework for interim disclosures, including a principle that entities disclose events and changes since the last annual reporting period that have a material effect on the entity. ASU 2025-11 is effective for public business entities for interim reporting periods within annual reporting periods beginning after December 15, 2027, and for all other entities for interim reporting periods within annual reporting periods beginning after December 15, 2028. Early adoption is permitted. The Company is currently evaluating the impact of ASU 2025-11 on its interim financial statements and related disclosures.

The Company does not believe that any other recently issued, but not yet effective, authoritative guidance, if currently adopted, would have a material impact on the Company’s financial statement presentation or disclosures.

Note 4: Property and Equipment

Property and equipment consisted of the following:

Depreciation expense for the years ended December 31, 2025 and 2024 totaled $8,327 and $664, respectively.

Note 5: SAFE Notes

During the years ended December 31, 2025 and 2024, the Company issued SAFE Notes in exchange for aggregate amounts of $2,893,800 and $8,190,000, respectively. For the year ended December 31, 2025, the Company received total cash proceeds of $2,993,800, consisting of $2,893,800 of cash from the issuance of SAFE Notes during the period and $100,000 of cash received from the subscription of a SAFE Note. For the year ended December 31, 2024, the Company received total cash proceeds of $8,590,000, with $8,190,000 cash from the issuance of SAFE Notes during the period and $400,000 of cash received from the subscription of a SAFE Note. As of December 31, 2024, the estimated fair value of the SAFE Notes totaled $10,783,385.

Prior to completion of the Merger, each SAFE Note holder gave consent to convert into shares of the Company’s common stock at the valuation cap reflected in each SAFE Note. In connection with the Merger, all SAFE Notes converted into 19,601,182 shares of the Company’s common stock, and the Company recorded a loss from the change in fair value on the date of conversion of approximately $39,834,049 (see Note 6).

Note 6: Fair Value Measurements

The following is a description of the valuation methodology and significant inputs used for each asset and liability measured at fair value on a recurring or nonrecurring basis, as well as the classification of the asset or liability within the fair value hierarchy.

The Company’s SAFE Notes were recorded at fair value on the consolidated balance sheets. The fair value of the Company’s SAFE Notes was based on significant inputs not observable in the market which cause the instrument to be classified as a Level 3 measurement with the fair value hierarchy. The valuation used weighted average probabilities estimated by management considering pay-offs under various scenarios as follows: (i) an equity financing where the SAFE Notes would convert into certain preferred stock; (ii) a liquidity event (change of control or initial public offering) where the SAFE Note holders would have an option to receive either a cash payment equal to the invested amount under such SAFE Note, or a number of shares of preferred stock equal to the invested amount divided by the liquidity price; and (iii) a dissolution event where the SAFE Note holders would have been entitled to receive a portion of the related proceeds equal to the purchase amount. Management estimated that equity financing or liquidity events were the predominant settlement scenarios at each period end. The Company determined the fair value of the SAFE Notes under the Monte Carlo simulation method which was used to estimate the future market value of invested capital (“MVIC”) of the Company at an equity financing event and the expected payment to the SAFE Note holders at each simulated MVIC value. The Company believed these assumptions would be made by a market participant in estimating the valuation of the SAFE Notes. The Company assessed these assumptions and estimates on an on-going basis as additional data impacting the assumptions and estimates was obtained while the SAFE Notes were outstanding. The determination of fair value for the Company’s SAFE Notes required significant judgment and the use of estimates. Additionally, the valuation scenarios described above reflected the original contractual terms of the SAFE Notes and anticipated early-stage financing structures. However, the Company completed the Merger with a concurrent issuance of common stock, and in connection with the Merger, the Company obtained consent from all holders of the SAFE Notes to convert their SAFE Notes into common stock rather than preferred stock. Changes in the fair value of the SAFE Notes were recognized on the consolidated statements of operations until their conversion to common stock occurred upon the Merger on September 5, 2025.

The key assumptions used in the Monte Carlo simulation are presented in the table below:

(1)Volatility was based on implied and historical volatility of the share price of peer companies.

(2)Risk-free rate based on the U.S. Treasury yield in effect at the time of SAFE Notes consistent with the expected term.

(3)The simulation considered 1–2 year term for equity event and 3.5 and 4-year term for liquidity event.

The following table presents a reconciliation of the liability measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as of December 31, 2025 and 2024:

Note 7: Commitments and Contingencies

In the normal course of business, the Company may be subject to contingencies, including litigation, investigations, claims and other legal proceedings, including those arising in the ordinary course of business. The Company recognizes a liability for such contingency if it determines it is probable that a loss has occurred and a reasonable estimate of the loss can be made. The Company may consider many factors in making these assessments including historical and the specific facts and circumstances of each matter. The Company has not had any litigation, investigations, claims or other legal proceedings for which it should recognize a liability. As such, the Company has not recorded any liability for these in the consolidated financial statements.

Note 8: Stockholders’ Equity (Deficit)

Common Stock

As of December 31, 2025, the Company had 300,000,000 shares of common stock authorized. Each share of its common stock has a par value of $0.0001 as of December 31, 2025.

The September 5, 2025 Private Placement

Concurrently with the consummation of the Merger, the Company also issued and sold 10,000,000 shares of our common stock in the Private Placement to certain accredited and institutional investors at a purchase price of $3.00 per share. The Company incurred offering costs of $2,909,740 in connection with the Private Placement, which were recorded as a reduction of the gross proceeds and recognized as a reduction to additional paid-in capital within stockholders’ equity.

Warrants

On September 5, 2025, the Company issued warrants to purchase an aggregate of 586,666 shares of its common stock, subject to customary anti-dilution adjustments for stock splits, stock dividends, and similar events, at an exercise price of $3.00 per share to placement agents in connection with the closing of the Private Placement (the “Placement Agent Warrants”). The Placement Agent Warrants expire on the earlier of (i)five years after the Merger Closing Date and (ii)three years after the Company’s shares of common stock are listed on a national securities exchange. The Warrants are indexed to the Company’s own stock and do not permit net cash settlement under circumstances outside the Company’s control, and thus were accounted for as equity-classified instruments in accordance with ASC 718Compensation - Stock Compensation andASC 815-40 Contracts in Entity’s Own Equity. The Warrants were measured at their grant-date fair value $1.617 per warrant share, using a Black-Scholes valuation model. The total fair value of $948,639 was recorded as an equity issuance cost and reflected as a reduction to additional paid-in capital, with a corresponding increase to additional paid-in capital for the warrant equity, resulting in no net impact to total stockholders’ equity.

Equity Incentive Plans

On August 29, 2025, the board of directors of Legacy Deep Fission approved the 2025 Equity Incentive Plan (the “Pre-Merger Equity Plan”), which permitted the grant of incentive stock options (“ISOs”), nonstatutory stock options (“NSOs”), stock appreciation rights (“SARs”), restricted stock awards (“RSAs”), restricted stock unit awards (“RSUs”), and other stock awards to employees, directors and consultants of Legacy Deep Fission. Subject to certain capitalization adjustments described in the Pre-Merger Equity Plan, the maximum aggregate number of shares of common stock that was issuable pursuant to the Pre-Merger Equity Plan was 84,351 shares. As of the effective date of the Merger, all outstanding options to purchase shares of Legacy Deep Fission common stock were converted into options to purchase shares of the Company’s common stock. Following the effective date of the Merger, no additional equity awards were permitted to be granted under the Pre-Merger Equity Plan; however, the Pre-Merger Equity Plan will continue to govern the terms and conditions of all outstanding equity awards previously granted under the Pre-Merger Equity Plan.

Awards granted prior to the Pre-Merger Equity Incentive Plan were approved by the board of directors and consisted of RSAs, with service-based vesting terms ranging from immediate vesting tofour years.

On September 5, 2025, in connection with the Merger, the board of directors and the stockholders of the Company approved the 2025 Equity Incentive Plan (the “2025 Plan”), which permits the grant of ISOs, NSOs, SARs, RSAs, RSUs, performance awards, and other awards to the Company’s employees, directors and consultants, including employees and consultants of the Company’s affiliates. The Company initially reserved 9,500,884 shares of common stock (the “Share Reserve”) for the issuance of awards under the 2025 Plan. The Share Reserve will automatically increase on January 1 of each year for a period of up tonine years commencing on January 1, 2027 and ending on (and including) January 1, 2035, in an amount equal to five percent (5%) of the total number of shares of common stock outstanding on December 31 of the preceding year; provided, however, that the board of directors may act prior to January 1 of a given year to limit the increase for such year to a lesser number of shares of common stock.

In the event of any merger, reorganization, recapitalization, reincorporation, or other such transaction as defined in the 2025 Plan (a “Capitalization Adjustment”), the board of directors is allowed to proportionately adjust the classes and maximum number of shares of common stock subject to the 2025 Plan and the maximum number of shares by which the Share Reserve may annually increase; the classes and maximum number of shares that may be issued pursuant to the exercise of ISOs; and the classes and number of securities and exercise price, strike price or purchase price of common stock subject to outstanding equity awards. No fractional shares or rights for fractional shares of common stock shall be issued under the 2025 Plan.

RSAs, RSUs, and Stock Options

During the years ended December 31, 2025 and 2024, the Company’s board of directors approved the issuances of RSAs, RSUs, and Stock Options to employees, officers, directors, and consultants. Stock-based compensation expense is measured based on the fair value of awards in accordance with ASC 718,Compensation - Stock Compensation. Equity-classified awards are measured at grant-date fair value and are not subsequently remeasured. Liability-classified awards are remeasured at fair value at each reporting date until settlement, with changes in fair value recognized in stock-based compensation expense. The cost of stock-based compensation is recognized over the requisite service period, which is generally the vesting period of the respective award. Grants ranged from immediate vesting to over four years. The determination of fair value requires significant judgment and the use of estimates as the Company does not have an observable stock price. Prior to the Company having an observable transaction for the sale of common stock, the Company estimated the fair value of common stock using invested capital multiple and discounted present value to arrive at equity available for common shareholders. Upon the Private Placement described above, the Company estimated the fair value of common stock using the price per share of the Private Placement, with a de-minimis discount for lack of marketability as the Company’s common stock does not trade in an active market. For restricted common stock awards, shares are issued concurrently with the issuance of restricted common stock.

A summary of the restricted common stock award activity during the year ended December 31, 2025, is as follows:

A summary of the RSU activity during the year ended December 31, 2025, is as follows:

No RSUs were granted during the year ended December 31, 2024.

A summary of the stock option activity during the year ended December 31, 2025, is as follows:

No stock options were granted during the year ended December 31, 2024. The stock options were valued at the grant date using the Black-Scholes pricing model using the range of inputs as indicated below:

The risk-free interest rate is the rate available as of the option date on zero-coupon U.S. government issues with a remaining term equal to the expected term of the option using the simplified approach. The Company currently estimates volatility by using the weighted average implied and historical volatility of the share price of peer companies. The Company has not paid dividends in the past and does not plan to pay any dividends in the foreseeable future.

The Company classifies stock-based compensation expense in its statement of operations in the same manner in which the award recipient’s costs are classified in the statement of operations. Total stock-based compensation expense for the years ended December 31, 2025 and 2024, was $8,424,803 and $1,171,287, respectively. Of the stock-based compensation expense recognized in the year ended December 31, 2025, $1,655,507 is related to a liability-classified award for a fixed number of shares that can also be settled in cash at the participant’s election upon vesting. The fair value of this award is based on the fair value of the underlying common stock and is remeasured at each reporting date until settlement. As of December 31, 2025, the Company recorded a liability of $1,655,507 related to this award, which is included in RSU liability award on the balance sheet.

As of December 31, 2025, the Company has unrecognized stock-based compensation expense of $14,742,022, which will be recognized over a weighted average period of 2.43 years.

Preferred Stock

As of December 31, 2025, the Company had 10,000,000 shares of preferred stock authorized at a par value of $0.0001. No preferred stock was issued and outstanding.

Note 9: Income Taxes

Income tax expense consisted of the following for the years ended December 31, 2025 and December 31, 2024:

The Company hadno deferred income tax expense for the years ended December 31, 2025 and 2024.

The provision for income taxes differs from the amount obtained by applying the federal statutory income tax rate as follows:

Deferred income taxes reflect the net tax effects of temporary differences between carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Realization of net deferred tax assets is dependent upon future earnings, if any, the timing and amount of which are uncertain. Significant components of the Company’s deferred tax assets and liabilities are as follows:

The Company regularly assesses the ability to realize deferred tax assets recorded based upon the weight of available evidence, including such factors as recent earnings history and expected future taxable income on a jurisdiction-by-jurisdiction basis. In the event that the Company changes its determination as to the amount of realizable deferred tax assets, the Company will adjust its valuation allowance with a corresponding impact to the provision for income taxes in the period in which such determination is made. Due to the uncertainty surrounding their realization, the Company has recorded a full valuation allowance against the net deferred tax assets. Accordingly, no deferred tax asset has been recorded on the balance sheets. The Company’s valuation allowance increased during 2025 and 2024 by $5,955,886 and $1,271,946, respectively, primarily due to the generation of net operating losses and the capitalization of research and development expenditures.

As of December 31, 2025 and 2024, the Company has net operating loss carryforwards for federal income tax purposes of approximately $9,101,980 and $1,960,671, respectively, which do not expire and may be available to offset future income tax liabilities, but will generally limit the net operating loss deduction to the lesser of the net operating loss carryover or 80% of a corporation’s taxable income. As of December 31, 2025 and 2024, the Company’s state net operating loss carryforwards were $15,663,544 and $2,950,882 which may be available to offset future income tax liabilities and start to expire in 2043.

The Internal Revenue Code of 1986, as amended, imposes restrictions on the utilization of net operating losses in the event of an “ownership change” of a corporation. Accordingly, a Company’s ability to use net operating losses may be limited as prescribed under Internal Revenue Code Section 382 (“Section 382”). Events which may cause limitations in the amount of the net operating losses that the Company may use in any one year include, but are not limited to, a cumulative ownership change of more than 50% over a three-year period. Utilization of the federal and state net operating losses may be subject to substantial annual limitation due to the ownership change limitations provided by the Section 382 and similar state provision.

The Company files income tax returns in the U.S. federal and various state jurisdictions with varying statutes of limitations.

Note 10: Related Party Transactions

The Company has signed a consulting agreement with a related party, Deep Isolation Nuclear, Inc., a company co-founded by Deep Fission’s co-founder and Chief Executive Officer, to develop generic technical and regulatory guidance for management of the Company. Deep Fission’s Chief Executive Officer currently serves as a member of the board of directors of Deep Isolation Nuclear, Inc. The Company has paid certain administrative expenses totaling $12,500 and $0 during the years ended December 31, 2025 and 2024, respectively.

During 2023, the Company received $10,000 in exchange for a loan payable to a related party that was due on demand and carried interest of 6% per annum. The loan was repaid in full, with interest, during the year ended December 31, 2024.

Note 11: Subsequent Events

In January 2026, the Company entered into a commitment with a supplier to purchase low-enriched uranium fuel at a cost of $9.2 million.

On February 5, 2026, the Company issued and sold 5,333,333 shares of common stock (the “Shares”) at a purchase price of $15.00 per share, to certain accredited and institutional investors pursuant to the subscription agreements for an aggregate purchase price of $80.0 million. The Company also issued 129,418 warrants to placement agents in conjunction with the financing. The aggregate net proceeds to the Company from the offering was approximately $76.0 million, after deducting fees to the placement agents and expenses payable by the Company. The Company is in the process of completing the valuation associated with associated with this transaction. As of the date the financial statements were available to be issued, the valuation has not been finalized.

In February 2026, the Company agreed to issue 188,701 additional shares to former holders of SAFE Notes related to the September 2025 financing, resulting in a reduction of the effective investment price from $3.92 to $2.90 per share. In connection with this issuance, the investors executed settlement agreements releasing the Company from any potential future claims related to these instruments.

In February 2026, the Company entered into a long-term lease for approximately 100 acres located within the Great Plains Industrial Park in Parsons, Kansas. The Company has commenced initial site development activities, including geological evaluation, borehole planning, and initial drilling activities, and are conducting geological surveys and site characterization studies at the site. These activities are intended to inform borehole design, drilling techniques, and site suitability for future reactor deployment. As part of the lease agreement, the Company has agreed to purchase the property from Great Plains Industrial Park for a purchase price of approximately $5 million, upon being granted a license for commercial operation of the reactor by the NRC.

Note 12: Restatement of Interim Financial Information (Unaudited)

As described in Note 2, the Company identified errors related to certain inputs and assumptions used in the valuation models for its SAFE Notes and stock-based compensation expense. These errors resulted in an overstatement of the fair value of SAFE Notes and an understatement of stock-based compensation expense in previously issued financial statements.

The Company has restated the previously issued quarterly (unaudited) financial data for the six-month periods ended June 30, 2024 and 2025, and the three- and nine-month periods ended September 30, 2024 and 2025, to correct these errors. The impacts of the restatement on the Company’s interim Consolidated Balance Sheets, Consolidated Statements of Operations, Consolidated Statements of Stockholders’ Equity (Deficit) and Consolidated Statements of Cash Flows for each of the affected quarterly periods are presented below. The misstatements did not have a material impact on reported cash flows during the period, as the valuations pertained to non-cash transactions.

Consolidated Balance Sheet – As of June 30, 2025

Consolidated Balance Sheet – As of September 30, 2025

Consolidated Statement of Operations – For the six months ended June 30, 2024

Consolidated Statement of Operations – For the three months ended September 30, 2024

Consolidated Statement of Operations – For the nine months ended September 30, 2024

Consolidated Statement of Operations – For the six months ended June 30, 2025

Consolidated Statement of Operations – For the three months ended September 30, 2025

Consolidated Statement of Operations – For the nine months ended September 30, 2025

Consolidated Statement of stockholders’ equity (deficit) for six months ended June 30, 2024

Consolidated Statement of stockholders’ equity (deficit) for nine months ended September 30, 2024

Consolidated Statement of stockholders’ equity (deficit) for three months ended September 30, 2024

Consolidated Statement of stockholders’ equity (deficit) for six months ended June 30, 2025

Consolidated Statement of stockholders’ equity (deficit) for nine months ended September 30, 2025

Consolidated Statement of stockholders’ equity (deficit) for three months ended September 30, 2025

Consolidated Statement of cash flows for the six months ended June 30, 2024

Consolidated Statement of cash flows for the nine months ended September 30, 2024

Consolidated Statement of cash flows for the six months ended June 30, 2025

Consolidated Statement of cash flows for the nine months ended September 30, 2025

EXHIBIT INDEX

• Filed herewith.

• Denotes management compensatory contract or arrangement.

˄ Furnished herewith and not “filed” for purposes of Section 18 of the Securities and Exchange Act of 1934, as amended (the “Exchange Act”). Such certifications will not be deemed to be incorporated by reference into any filings under the Securities Act of 1933 or the Exchange Act, except to the extent that the registrant specifically incorporates by reference.

§ Schedules have been omitted pursuant to Item 601(a)(5) of Regulation S-K promulgated by the SEC. The Company agrees to furnish supplementally a copy of any omitted schedule or exhibit to the SEC upon request.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this Annual Report on Form 10-K to be signed on its behalf by the undersigned, thereunto duly authorized.