Quantum-Si Inc

Rule 10b5-1 Trading Arrangements

Effective September 9, 2025, in connection with estate planning, Dr. Rothberg, who is amember of the Board, acting on his own behalf and on behalf of entities owned by trusts created for the benefit of his children, entered into a 10b5-1 sales plan (the “Sales Plan”) intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act. The Sales Plan provides for the sale of up to 8,973,841 shares of the Company’s Class A common stock beginning on January 14, 2026 and shall terminate upon the earliest of (i)January 14, 2027, (ii) the sale of 8,973,841 shares of the Company’s Class A common stock, or (iii) the occurrence of any of the other terminating events set forth in the Sales Plan.

Other than as disclosed above, during the quarter ended September 30, 2025, no other officers or directors, as defined in Rule 16a-1(f), adopted, modified orterminated a “Rule 10b5-1 trading arrangement” or a “non-Rule 10b5-1 trading arrangement,” as defined in Item 408 of Regulation S-K.

Departure of Certain Officers

On November 3, 2025, Quantum-Si Incorporated (the “Company”) entered into a separation agreement (the “Separation Agreement”) with Todd Bennett, the Company’s Chief Commercial Officer. Pursuant to the Separation Agreement, Mr. Bennett’s employment with the Company will terminate as of November 7, 2025 (the “Separation Date”). Pursuant to the terms of the Quantum-Si Incorporated Executive Severance Plan, the Separation Agreement provides, among other things, that (i) the Company will make a one-time lump sum separation payment to Mr. Bennett in an amount equal to $318,750; and (ii) if Mr. Bennett enrolls in COBRA coverage, the Company will pay the employer portion of Mr. Bennett’s COBRA health insurance for the lesser of the period ending August 31, 2026 or the month in which Mr. Bennett becomes eligible to participate in a subsequent employer’s COBRA benefits. All unvested options and restricted stock units will be forfeited as of the Separation Date. The Separation Agreement also includes a release and waiver by Mr. Bennett and other customary provisions.

The foregoing description of the Separation Agreement is not complete and is qualified in its entirety by reference to the full text of the Separation Agreement, a copy of which is filed as Exhibit 10.5 to this quarterly report on Form 10-Q.