[Form 4] Quantum-Si Inc Insider Trading Activity

Rhea-AI Filing Summary

Jeffry R. Keyes, Chief Financial Officer of Quantum-Si Inc. (QSI), reported two routine stock sales tied to vested restricted stock units. The filing shows sales on 09/22/2025 and 09/23/2025 of 3,873 shares each day under a mandatory sell-to-cover provision used to satisfy federal, state and local tax withholding on vesting RSUs. The weighted average sale prices were $1.6826 (shares sold ranged $1.64–$1.72) and $1.635 (shares sold ranged $1.57–$1.79). Beneficial ownership reported after the transactions was 1,175,697 shares following the 09/22 sale and 1,171,824 shares following the 09/23 sale. The filer notes the sell-to-cover is mandatory and not subject to trustee election; the form was signed by an attorney-in-fact on 09/24/2025.

Positive

• Mandatory sell-to-cover sales were disclosed, clarifying the transactions were for tax withholding rather than discretionary disposition
• Detailed price information and ranges provided for both sale dates increases transparency
• Reporting shows substantial retained ownership (over 1.17 million shares) after the transactions

Negative

• Insider sold a total of 7,746 shares across two days, reducing direct holdings by that amount
• Weighted average sale prices were low (around $1.63–$1.68), which may reflect prevailing market price at the time

Insights

Financial Analyst

TL;DR: Routine, non-discretionary insider sales to cover RSU tax withholding; immaterial to valuation absent other disclosures.

The filing discloses two small, mandatory sell-to-cover transactions totaling 7,746 shares executed over two days at modest prices near the low-$1.60s. Because the sales are described as mandatory for tax withholding on vested RSUs and the reporting person retains over 1.17 million shares after the transactions, this is a routine liquidity event rather than an opportunistic insider sale. There is no indication of additional derivative transactions or discretionary disposals in this Form 4.

Corporate Governance Expert

TL;DR: Filing shows compliant disclosure of required sell-to-cover activity; governance controls appear to function as intended.

The report clearly states the sales resulted from a predetermined sell-to-cover provision established at grant, which the reporting person could not alter. That transparency supports good insider disclosure practices. The signature by an attorney-in-fact and the inclusion of weighted average prices and price ranges align with reporting standards. No governance red flags or unexplained disposals are present in this submission.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Keyes Jeffry R.

(Last) (First) (Middle)

C/O QUANTUM-SI INCORPORATED

29 BUSINESS PARK DRIVE

(Street)

BRANFORD CT 06405

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Quantum-Si Inc [ QSI ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Financial Officer

3. Date of Earliest Transaction (Month/Day/Year)
09/22/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	09/22/2025		S(1)		3,873	D	$1.6826(2)	1,175,697	D
Class A Common Stock	09/23/2025		S(1)		3,873	D	$1.635(3)	1,171,824	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Represents shares sold pursuant to a mandatory Quantum-Si sell-to-cover provision for required federal, state and local withholding taxes in connection with the vesting of previously granted restricted stock units. Individual is not able to alter this mandatory sell-to-cover provision that is enacted at the grant date of the related restricted stock unit award.

2. Represents the weighted average sales price per share. The shares sold at prices ranging from $1.64 to $1.72 per share. Full information regarding the number of shares sold 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.

3. Represents the weighted average sales price per share. The shares sold at prices ranging from $1.57 to $1.79 per share. Full information regarding the number of shares sold 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.

	/s/ Christian LaPointe, Ph.D., Attorney-in-Fact.	09/24/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

Who filed this Form 4 for Quantum-Si Inc. (QSI)?

The filer is Jeffry R. Keyes, identified as Chief Financial Officer and a reporting person of Quantum-Si Inc.

Why were shares sold in this Form 4 for QSI?

The filing states the sales were mandatory sell-to-cover transactions to satisfy federal, state and local tax withholding on vested restricted stock units.

How many shares were sold and on what dates?

A total of 7,746 shares were sold: 3,873 shares on 09/22/2025 and 3,873 shares on 09/23/2025.

What prices were the shares sold at?

Weighted average prices reported were $1.6826 for the 09/22 sale (range $1.64–$1.72) and $1.635 for the 09/23 sale (range $1.57–$1.79).

How many shares did the reporting person own after the transactions?

Beneficial ownership post-transactions is reported as 1,175,697 shares after 09/22 and 1,171,824 shares after 09/23.