Quantum-Si files notice for 187,500-share sale

Quantum-Si Incorporated notice of proposed sale of 187,500 Class A Common Stock linked to Restricted Stock Unit Vesting on 04/22/2026.

Rhea-AI Filing Summary

Quantum-Si Incorporated notice of proposed sale of 187,500 Class A Common Stock linked to Restricted Stock Unit Vesting on 04/22/2026. The filing also records 8,655 shares sold on 03/20/2026 by Morgan Stanley Smith Barney LLC as shown. The securities are described as equity compensation for services rendered.

Key Figures

Proposed sale: 187,500 shares Recent affiliate sale: 8,655 shares Sale purpose: Equity compensation

3 metrics

Proposed sale 187,500 shares Restricted Stock Unit Vesting on <date>04/22/2026</date>

Recent affiliate sale 8,655 shares Sold on <date>03/20/2026</date>

Sale purpose Equity compensation Described as for services rendered

Key Terms

Restricted Stock Unit Vesting, Form 144, Class A Common Stock

3 terms

Restricted Stock Unit Vesting financial

"Restricted Stock Unit Vesting | Quantum-Si Incorporated | 187500 | 04/22/2026"

Form 144 regulatory

"Filer Information | Issuer Information | Securities To Be Sold"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

Class A Common Stock financial

"Class A Common Stock | 04/22/2026 | Restricted Stock Unit Vesting"

Class A common stock is a category of a company’s shares that carries a specific set of ownership rights—most commonly defined voting power and claims on dividends—set out in the company’s charter. For investors it matters because the class determines how much influence you have over corporate decisions, the share’s likely dividend and trading behavior, and how it compares in value to other share classes, like choosing a particular seat with different privileges at the company’s decision-making table.

FAQ

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

What does Quantum-Si (QSI) Form 144 report?

It reports a proposed sale of 187,500 Class A shares tied to RSU vesting on 04/22/2026. The filing notes these shares are equity compensation for services rendered and lists a prior sale of 8,655 shares on 03/20/2026.

Who is listed as the broker or dealer on the QSI Form 144?

The filing lists Morgan Stanley Smith Barney LLC at 1 New York Plaza, New York. That broker-dealer is shown in connection with the reported sale activity and proposed transaction on the specified dates.

Are the 187,500 shares newly vested or previously outstanding for QSI?

The filing ties the 187,500 shares to a Restricted Stock Unit Vesting event dated 04/22/2026, indicating these shares arise from equity compensation vesting rather than a primary issuance disclosed here.

What recent sales by affiliates does the QSI Form 144 show?

It shows an affiliate sale of 8,655 Class A shares executed on 03/20/2026. That transaction is listed in the "Securities Sold During The Past 3 Months" section of the notice.

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

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Accepted by SEC EDGAR 04/22/2026 - 04:50 PM EDT Learn about SEC filing dates

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	74763	74799.39	196431273	04/20/2026	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	04/22/2026	Restricted Stock Unit Vesting	Quantum-Si Incorporated			187500	04/22/2026	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	03/20/2026	8655	7246.08

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	04/22/2026
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)