X0306 4 2022-06-14 0001816431 Quantum-Si Inc QSI 0001076352 ROTHBERG JONATHAN M C/O QUANTUM-SI INCORPORATED 530 OLD WHITFIELD STREET GUILFORD CT 06437 true true true Interim CEO Class A Common Stock 2022-06-14 4 P 0 25561 3.0975 A 2568443 D Class A Common Stock 6230108 I By 2012 JMR Trust Common, LLC Class A Common Stock 1250000 I By NVR TR, LLC Class A Common Stock 1250000 I By JNR TR, LLC Class A Common Stock 1250000 I By JAR TR, LLC Class A Common Stock 1250000 I By GBR TR, LLC Class A Common Stock 1250000 I By EJR TR, LLC Class A Common Stock 1917067 I By 23rd Century Capital LLC Class A Common Stock 273422 I By Bonnie E Gould Rothberg MD Class B Common Stock 17943750 I By 4C Holdings I, LLC Class B Common Stock 1993750 I By 4C Holdings V, LLC Represents the weighted average purchase price per share. The shares were purchased at prices ranging from $3.065 to $3.1261 per share. Full information regarding the number of shares purchased at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. Dr. Rothberg is the sole manager of 4C Holdings I, LLC, 4C Holdings V, LLC, 2012 JMR Trust Common, LLC, NVR TR, LLC, JNR TR, LLC, JAR TR, LLC, GBR TR, LLC and EJR TR, LLC. Dr. Rothberg is the spouse of Bonnie E. Gould Rothberg MD and Dr. Rothberg's son is the manager of 23rd Century Capital LLC. Dr. Rothberg disclaims beneficial ownership of the shares held by his spouse and 23rd Century Capital LLC. Shares previously held by 2012 JMR Trust Common, LLC that were distributed to NVR TR, LLC, JNR TR, LLC, JAR TR, LLC, GBR TR, LLC and EJR TR, LLC. /s/ Samantha Silver, Attorney-in-Fact 2022-06-16