JONATHAN M. ROTHBERG - 09 Sep 2025 SCHEDULE 13D/A Report for Quantum-Si Inc Class A common stock, par value $0.0001 per share, Class B common stock, par value $0.0001 per share (QSI)

Filing Manager: JONATHAN M. ROTHBERG
Reporting Manager: ROTHBERG JONATHAN M.
Security: Quantum-Si Inc Class A common stock, par value $0.0001 per share, Class B common stock, par value $0.0001 per share
Symbol: QSI
Shares outstanding: 19,937,500 shares
Disclosed Ownership: 19,937,500 shares
Ownership: 100%
Form type: SCHEDULE 13D/A
Filing time: 11 Sep 2025, 17:04:02 UTC
Date of event: 09 Sep 2025
Previous filing: 31 Dec 2024
SEC: View on sec.gov

Reporting Managers (6)

Name	Ownership	Shares Owned	sole voting power	shared voting power	Signature	Title	CIK
ROTHBERG JONATHAN M	7.8%	14,276,415	12,085,926	2,190,489	/s/ Jonathan M. Rothberg	Jonathan M. Rothberg, Ph.D.	0001076352
ROTHBERG JONATHAN M.	100%	19,937,500	19,937,500	0	/s/ Jonathan M. Rothberg	Jonathan M. Rothberg, Ph.D.
23rd Century Capital LLC	1.05%	1,917,067		1,917,067	/s/ Jonathan M. Rothberg	Jonathan M. Rothberg, Ph.D., Member
2012 JMR Trust Common, LLC	0%				/s/ Jonathan M. Rothberg	Jonathan M. Rothberg, Ph.D., Manager
4C Holdings I, LLC	90%	17,943,750		17,943,750	/s/ Jonathan M. Rothberg	Jonathan M. Rothberg, Ph.D., Manager
4C Holdings V, LLC	10%	1,993,750		1,993,750	/s/ Jonathan M. Rothberg	Jonathan M. Rothberg, Ph.D., Manager