Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2026
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The accompanying unaudited interim condensed consolidated financial statements and related disclosures are prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") applicable to interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S- X. Our condensed consolidated financial statements include the accounts of System1, Inc. and its subsidiaries. All intercompany accounts and transactions have been eliminated in the consolidation. Our fiscal year ends on December 31, 2026. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025, as filed with the Securities and Exchange Commission on March 11, 2026. In our opinion, the condensed consolidated financial statements include all adjustments of a normal recurring nature necessary for the fair statement of our financial position, results of operations, and cash flows. The results of operations for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the full fiscal year ending December 31, 2026 or future operating periods. There have been no changes to our significant accounting policies described in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 that have had a material impact on our condensed consolidated financial statements and related notes. On June 10, 2025, we filed a certificate of amendment to our Amended and Restated Certificate of Incorporation with the Secretary of State of Delaware to effect a 1-for-10 reverse stock split of the Class A and Class C common stock (the "Reverse Stock Split"). All share data and per share data amounts included in this Form 10-Q have been retrospectively adjusted to reflect the effect of the Reverse Stock Split. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the reported amounts of revenue and expenses during the reporting period. Management's estimates are based on historical information available as of the date of the condensed consolidated financial statements and various other assumptions that we believe are reasonable under the circumstances. Actual results could differ from those estimates. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, valuation of goodwill, intangible assets, and long-lived assets, valuation and recognition of stock-based compensation awards and income taxes. On an ongoing basis, management evaluates our estimates compared to historical experience and trends, which form the basis for making judgments about the carrying value of assets and liabilities. Risks We are subject to certain business and operational risks, including competition from alternative technologies, as well as dependence on key Advertising Partners, key employees, key contracts, and growth to achieve our business and operational objectives. Concentrations As of March 31, 2026, we had one paid search advertising partnership agreement with Google, and one paid search advertising partnership agreement with Microsoft. The agreement with Google (our largest Advertising Partner by revenue) is in effect through September 30, 2027. We had a second Google agreement that originally was scheduled to remain in effect through February 28, 2027, but was terminated for convenience by Google effective as of February 10, 2026. The agreement with Microsoft (our next largest Advertising Partner by revenue) is in effect through December 31, 2026. Under certain circumstances, each of these agreements may be terminated by either us or the respective Advertising Partner immediately, or with minimal notice. Accounting Pronouncements Not Yet Adopted In November 2024, the Financial Accounting Standards Board issued ASU No. 2024-03, Income Statement Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40), which improves the disclosures about a public business entity's expenses and requires detailed information about the types of expenses in commonly presented expense financial statement captions. This guidance will be effective for the annual periods beginning with the year ending December 31, 2027 and interim periods during the year ending December 31, 2028. Early adoption is permitted. Upon adoption, the guidance can be applied prospectively or retrospectively. We are evaluating the effect that this guidance will have on our condensed consolidated financial statements and related disclosures. In September 2025, the Financial Accounting Standards Board issued ASU No. 2025-06, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software, which amends certain aspects of the accounting for and disclosure of software costs. This guidance will be effective for the annual periods beginning with the year ending December 31, 2028 and interim periods during the year ending December 31, 2028. Early adoption is permitted. Upon adoption, the guidance can be applied prospectively or retrospectively. We are evaluating the effect that this guidance will have on our condensed consolidated financial statements and related disclosures.

The accompanying unaudited interim condensed consolidated financial statements and related disclosures are prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") applicable to interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-

X. Our condensed consolidated financial statements include the accounts of System1, Inc. and its subsidiaries. All intercompany accounts and transactions have been eliminated in the consolidation. Our fiscal year ends on December 31, 2026. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025, as filed with the Securities and Exchange Commission on March 11, 2026.

In our opinion, the condensed consolidated financial statements include all adjustments of a normal recurring nature necessary for the fair statement of our financial position, results of operations, and cash flows. The results of operations for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the full fiscal year ending December 31, 2026 or future operating periods.

There have been no changes to our significant accounting policies described in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 that have had a material impact on our condensed consolidated financial statements and related notes.

On June 10, 2025, we filed a certificate of amendment to our Amended and Restated Certificate of Incorporation with the Secretary of State of Delaware to effect a 1-for-10 reverse stock split of the Class A and Class C common stock (the "Reverse Stock Split"). All share data and per share data amounts included in this Form 10-Q have been retrospectively adjusted to reflect the effect of the Reverse Stock Split.

The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the reported amounts of revenue and expenses during the reporting period. Management's estimates are based on historical information available as of the date of the condensed consolidated financial statements and various other assumptions that we believe are reasonable under the circumstances. Actual results could differ from those estimates.

Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, valuation of goodwill, intangible assets, and long-lived assets, valuation and recognition of stock-based compensation awards and income taxes. On an ongoing basis, management evaluates our estimates compared to historical experience and trends, which form the basis for making judgments about the carrying value of assets and liabilities.

We are subject to certain business and operational risks, including competition from alternative technologies, as well as dependence on key Advertising Partners, key employees, key contracts, and growth to achieve our business and operational objectives.

As of March 31, 2026, we had one paid search advertising partnership agreement with Google, and one paid search advertising partnership agreement with Microsoft. The agreement with Google (our largest Advertising Partner by revenue) is in effect through September 30, 2027. We had a second Google agreement that originally was scheduled to remain in effect through February 28, 2027, but was terminated for convenience by Google effective as of February 10, 2026. The agreement with Microsoft (our next largest Advertising Partner by revenue) is in effect through December 31, 2026. Under certain circumstances, each of these agreements may be terminated by either us or the respective Advertising Partner immediately, or with minimal notice.

In November 2024, the Financial Accounting Standards Board issued ASU No. 2024-03, Income Statement Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40), which improves the disclosures about a public business entity's expenses and requires detailed information about the types of expenses in commonly presented expense financial statement captions. This guidance will be effective for the annual periods beginning with the year ending December 31, 2027 and interim periods during the year ending December 31, 2028. Early adoption is permitted. Upon adoption, the guidance can be applied prospectively or retrospectively. We are evaluating the effect that this guidance will have on our condensed consolidated financial statements and related disclosures.

In September 2025, the Financial Accounting Standards Board issued ASU No. 2025-06, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software, which amends certain aspects of the accounting for and disclosure of software costs. This guidance will be effective for the annual periods beginning with the year ending December 31, 2028 and interim periods during the year ending December 31, 2028. Early adoption is permitted. Upon adoption, the guidance can be applied prospectively or retrospectively. We are evaluating the effect that this guidance will have on our condensed consolidated financial statements and related disclosures.