FORM 10-Q (Mark One)☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026 or TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ________ to _________Commission File Number: 001-39486 QUANTUM-SI INCORPORATED (Exact name of registrant as specified in its charter)_____________________________________________________________ 85-1388175 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) 29 Business Park DriveBranford, Connecticut06405(Address of principal executive offices)(Zip Code) (866)688-7374(Registrant’s telephone number, including area code) Not applicable(Former name, former address and former fiscal year, if changed since last report) Securities registered pursuant to Section 12(b) of the Act: Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the SecuritiesExchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports),and (2) has been subject to such filing requirements for the past 90 days. Yes☒No Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submittedpursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that theregistrant was required to submit such files). Yes☒No Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smallerreporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smallerreporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act. If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes☐No☒ As of May4, 2026, the registrant had 197,822,663 shares of Class A common stock outstanding and 19,937,500 shares of Class Bcommon stock outstanding. QUANTUM-SI INCORPORATEDTABLE OF CONTENTS Cautionary Note Regarding Forward-Looking Statements Part I.Financial Information5Item 1.Financial Statements5Condensed Consolidated Balance Sheets as of March 31, 2026, and December 31, 2025(unaudited)5Condensed Consolidated Statements of Operations and Comprehensive Loss for the three months endedMarch 31, 2026 and 2025(unaudited)6Condensed Consolidated Statements of Changes in Stockholders’ Equity for the three months ended March31, 2026 and 2025(unaudited)7Condensed Consolidated Statements of Cash Flows for the three months ended March 31, 2026 and 2025(unaudited)8Notes to Condensed Consolidated Financial Statements (unaudited)9Item 2.Management’s Discussion and Analysis of Financial Condition and Results of Operations24Item 3.Quantitative and Qualitative Disclosures About Market Risk31Item 4.Controls and Procedures31 Part II.Other Information33Item 1.Legal Proceedings33Item 1A.Risk Factors33Item 2.Unregistered Sales of Equity Securities and Use of Proceeds33Item 3.Defaults Upon Senior Securities33Item 4.Mine Safety Disclosures33Item 5.Other Information33Item 6.Exhibits34Signatures35 In this Quarterly Report on Form 10-Q, the terms “we”, “us”, “our”, the “Company” or “Quantum-Si” mean Quantum-Si Incorporatedand our subsidiaries. Quantum-Si Incorporated was incorporated in Delaware on June 10, 2020. CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS This Quarterly Report on Form 10-Q includes forward-looking statements within the meaning of Section 27A of the Securities Act of1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)and subject to the safe harbor created by the Private Securities Litigation Reform Act of 1995, that relate to future events, our futureoperations or financial performance, or our plans, strategies and prospects. These statements are based on the beliefs and assumptionsof our management team. Although we believe that our plans, intentions and expectations reflected in or suggested by these forward-looking statements are reasonable, we cannot assure you that we will achieve or realize these plans, intentions or expectations.Forward-looking statements are inherently subject to risks, uncertainties and assumptions. Generally, statements that are not historicalfacts, including statements concerning possible or assumed future actions, business strategies, events or performance, are forward-looking statements. The actual results may differ from its ex