ONE STOP SYSTEMS, INC.

INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

To the Board of Directors and Stockholders of

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheets of One Stop Systems, Inc. (the “Company”) as of December 31, 2025 and 2024, the related consolidated statements of operations, comprehensive loss, stockholders’ equity, and cash flows for each of the years then ended, and the related notes (collectively, the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the years then ended, in conformity with accounting principles generally accepted in the United States of America.

Emphasis of a Matter - Discontinued Operations

As discussed in Note 18 to the consolidated financial statements, on December 30, 2025, the Company completed the sale of its wholly owned subsidiary, One Stop Systems, GmbH, which wholly owned Bressner Technology GmbH (“Bressner”). Management evaluated and determined that all of the criteria to report Bressner as discontinued operations were met. As a result, the financial results of Bressner have been presented as discontinued operations for all periods presented in the consolidated financial statements.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (“PCAOB”) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing separate opinions on the critical audit matter or on the accounts or disclosures to which it relates.

Inventory Reserve – Refer to Note 5 to the Consolidated Financial Statements

Critical Audit Matter Description

The inventory reserve for obsolete and slow-moving inventory is based on the Company's estimates of future salability in addition to retrospective review of annual usage. In specific instances, management will apply partial reserve percentages. As such, management’s estimate of the inventory reserve is subject to significant judgment, especially with respect to the use of future demand forecasts.

Our assessment of management’s evaluation of the above referenced matter related to inventory reserve is significant to our audit because the amounts are material to the consolidated financial statements and the assessment process involves significant judgment.

How the Critical Audit Matter Was Addressed in the Audit

Our primary audit procedures related to the Company’s inventory reserve included the following:

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We obtained an understanding and evaluated the appropriateness of the Company's methodology for estimating the inventory reserve, including their use of historical inventory turnover data and their assumptions used to determine slow-moving and obsolete inventory.

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We tested the underlying data used by the Company to determine their estimates for relevance and reliability, including testing of the historical sales data to ensure completeness and accuracy of the reserve.

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We tested the mathematical accuracy of management’s calculations of the inventory reserve.

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We performed a lower of cost or net realizable value analysis to ensure inventory valuation is in accordance with U.S. generally accepted accounting principles.

HASKELL & WHITE LLP

We have served as the Company’s auditor since 2017.

Irvine, California

March 18, 2026