Morgan Stanley Smith Barney to sell QSI Class A shares

Quantum-Si Incorporated subject of a Form 144 notice relating to proposed sales of Class A Common Stock by Morgan Stanley Smith Barney LLC.

Accepted by SEC EDGAR 03/24/2026 - 09:10 AM EDT Learn about SEC filing dates

Rhea-AI Filing Summary

Quantum-Si Incorporated subject of a Form 144 notice relating to proposed sales of Class A Common Stock by Morgan Stanley Smith Barney LLC. The filing lists 8,655 shares and references prior restricted stock unit vesting of 21,676 units on 03/15/2024.

The notice also records sales in the past three months on 12/22/2025 of 8,627 shares. The filing is a broker-serviced resale notice under the SEC resale rules.

Insights

Securities Attorney

Form 144 filed for resale of Class A shares by a broker-dealer affiliate.

The filing lists 8,655 shares of Class A Common Stock associated with Morgan Stanley Smith Barney LLC and notes 21,676 restricted stock units vested on 03/15/2024. It also documents prior reported sales of 8,627 shares on 12/22/2025.

Under resale-rule mechanics, this notice permits a broker to effect sales subject to the rule's conditions; cash-flow treatment and final sale timing are not stated in the excerpt. Subsequent filings or broker reports will show execution details and proceeds.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does QSI's Form 144 filed by Morgan Stanley Smith Barney mean?

It notifies the SEC of an intended resale of Class A Common Stock by Morgan Stanley Smith Barney. The filing lists 8,655 shares and documents prior sales and vesting events tied to the account.

How many RSUs vested for QSI as shown in this filing?

The filing shows 21,676 Restricted Stock Units vested on 03/15/2024. The entry is labeled as equity compensation for services rendered and is recorded with that vesting date.

Did the filing record any recent sales for QSI shares?

Yes, it records sales during the past three months of 8,627 shares on 12/22/2025. The entry appears under 'Securities Sold During The Past 3 Months.'

Who is the broker named in the Form 144 for QSI?

The broker-dealer identified is Morgan Stanley Smith Barney LLC with an address at 1 New York Plaza, 38th Floor, New York, NY. The broker is listed as the selling intermediary in the filing.

Does the Form 144 show sale proceeds or pricing for the listed shares?

The excerpt does not state explicit cash proceeds or a per-share sale price for the listed resale. Execution details and proceeds would appear in subsequent trade reports or broker disclosures.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001557736
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Quantum-Si Inc
SEC File Number	001-39486
Address of Issuer	29 BUSINESS PARK DRIVE BRANFORD CONNECTICUT 06405
Phone	(203) 458-7100
Name of Person for Whose Account the Securities are To Be Sold	Keyes Jeffry R.
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Class A Common Stock	Morgan Stanley Smith Barney LLC 1 New York Plaza 38th Floor New York NY 10004	8655	7246.08	196431273	03/20/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Class A Common Stock	03/15/2024	Restricted Stock Unit Vesting	Quantum-Si Incorporated			21676	03/15/2024	Equity compensation for services rendered

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Morgan Stanley Smith Barney LLC 1 New York Plaza 38th Floor New York NY 10004	Class A Common Stock	12/22/2025	8627	11008.05

144: Remarks and Signature

Remarks	Shares sold to cover tax withholding obligations in connection with the vesting of restricted stock units. The sale is mandated by the Issuers election to require the satisfaction of tax withholding obligations through a sell to cover transaction and does not represent a discretionary trade by the reporting person.
Date of Notice	03/24/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Christian LaPointe, Ph.D., Attorney-in-Fact
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)