Quantum-Si (QSI) CPO Vieceli awarded options and 391,681 RSUs

Rhea-AI Filing Summary

Quantum-Si Inc Chief Product Officer John S. Vieceli received new equity awards. On March 12, 2026, he was granted options to buy 468,508 shares of Class A common stock at an exercise price of $0.976 per share, vesting in equal quarterly installments beginning on June 20, 2026 until fully vested, subject to continued service.

He also received 391,681 restricted stock units, each representing one share of common stock upon vesting, on the same vesting schedule starting June 20, 2026. Following these awards, Vieceli directly holds 1,192,654 shares of Class A common stock. These are compensation-related grants rather than open-market purchases or sales.

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

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Vieceli John S.

(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 Product Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/12/2026

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	03/12/2026		A		391,681(1)	A	$0	1,192,654	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
Stock Option (Right to Buy)	$0.976	03/12/2026		A		468,508		(2)	03/12/2036	Class A Common Stock	468,508	$0	468,508	D

Explanation of Responses:

1. The grant consists of restricted stock units ("RSUs"). Each RSU represents the right to receive one share of common stock upon vesting. The RSUs shall vest in 16 equal quarterly installments beginning on June 20, 2026 until fully vested, subject to continued service through the applicable vesting date.

2. The shares underlying this option shall vest in equal quarterly installments beginning on June 20, 2026 until fully vested, subject to continued service through the applicable vesting dates.

	/s/ Christian LaPointe, Ph.D., Attorney-in-Fact.	03/16/2026
	** 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

What did Quantum-Si (QSI) disclose about John S. Vieceli’s new stock options?

Quantum-Si granted Chief Product Officer John S. Vieceli options for 468,508 Class A shares at an exercise price of $0.976. These options vest in equal quarterly installments starting June 20, 2026, and continue until fully vested, conditioned on his continued service.

What restricted stock units did Quantum-Si (QSI) grant to John S. Vieceli?

Quantum-Si granted John S. Vieceli 391,681 restricted stock units, each convertible into one share of common stock. The RSUs vest in 16 equal quarterly installments beginning June 20, 2026, subject to his continued service through each vesting date.

Are John S. Vieceli’s Quantum-Si (QSI) equity grants open-market transactions?

No, the Form 4 shows compensation-related equity grants, not open-market trades. Both the stock options and restricted stock units were awarded at a $0.00 grant price and will vest over time, reflecting incentive compensation rather than buying or selling shares in the market.

How many Quantum-Si (QSI) shares does John S. Vieceli hold after these grants?

After the reported transactions, John S. Vieceli directly holds 1,192,654 shares of Quantum-Si Class A common stock. This figure comes from the Form 4’s post-transaction ownership line for the non-derivative shares, reflecting his updated equity position.

What are the vesting conditions for Quantum-Si (QSI) RSUs granted to John S. Vieceli?

The RSUs vest in 16 equal quarterly installments starting June 20, 2026, and each vested unit delivers one share of common stock. Vesting requires John S. Vieceli to remain in service with the company through each applicable vesting date, according to the disclosure.