Quantum-Si Inc

Rule 10b5-1 Trading Arrangements

During the quarter ended June 30, 2026, no 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.

Organizational Restructuring Program

On August 10, 2026, the Company committed to an organizational restructuring program (the “2026 Restructuring Program”) designed to restructure resources focused specifically on its Proteus TM development program as well as other adjustments to streamline general and administrative expenses to align with the estimated Proteus launch. As a result, the Company is terminating approximately 20% of its 152 employee workforce. In connection with the restructuring, the Company expects that it will recognize one-time cash charges related to severance and other benefits of approximately $2.6 million in the second half of 2026, and expects substantially all related cash expenditures to be incurred in the second half of 2026. In addition, the Company expects to recognize non-cash expense related to stock option modifications in the second half of 2026 in the amount of approximately $0.1 million. The Company expects to substantially complete the 2026 Restructuring Program by the end of 2026. The severance and other benefits related charge, as well as the expense related to stock option modifications, are subject to a number of assumptions, and actual results may differ materially. The Company may also incur additional costs not currently contemplated due to events that may occur as a result of, or that are associated with, the 2026 Restructuring Program.

Departure of a Certain Officer

In connection with the 2026 Restructuring Program, on August 10, 2026, the Company and John Vieceli, Ph.D., the Company’s Chief Product Officer, mutually agreed to end their employment relationship effective August 13, 2026 (the “Separation Date”). Dr. Vieceli is subject to the Amended and Restated Quantum-Si Incorporated Executive Severance Plan effective November 1, 2024 (the “Severance Plan”). Dr. Vieceli’s severance benefits under the Severance Plan are conditioned upon his timely execution and delivery to the Company of a Release (as defined in the Severance Plan), non-revocation of such Release, and compliance with the other benefit conditions set forth in the Severance Plan. Pursuant to the terms of the Severance Plan, Dr. Vieceli is entitled to, among other things, (i) a one-time lump sum separation payment in an amount equal to $333,750; and (ii) if Dr. Vieceli enrolls in COBRA coverage, payment by the Company of the employer portion of Dr. Vieceli’s COBRA health insurance premiums until the earlier of May 31, 2027 and the month in which Dr. Vieceli becomes eligible to participate in a subsequent employer’s health benefits. All unvested options and restricted stock units will be forfeited as of the Separation Date.

The material terms of Dr. Vieceli’s separation are described in, and the Severance Plan is filed as, Exhibit 10.18 to the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2025, which is incorporated by reference herein.