QSI files Form 144 to sell 21,676 Class A shares

Quantum-Si Incorporated filed a Form 144 notice for the proposed sale of 21,676 shares of Class A Common Stock associated with Restricted Stock Unit vesting on 06/20/2026.

Rhea-AI Filing Summary

Quantum-Si Incorporated filed a Form 144 notice for the proposed sale of 21,676 shares of Class A Common Stock associated with Restricted Stock Unit vesting on 06/20/2026. The filing records a prior sale of 74,763 shares on 04/20/2026 by Jeffry Keyes.

Insights

Insider Transactions Analyst

Notice of proposed sale tied to RSU vesting; prior sale also disclosed.

The filing lists a proposed resale of 21,676 shares on 06/20/2026 described as Restricted Stock Unit Vesting, indicating the shares arose from compensation. The notice formalizes an intended disposal under resale rules.

It also discloses a prior transaction of 74,763 shares on 04/20/2026 by Jeffry Keyes. Cash‑flow treatment and planned sale method are not stated in the excerpt; subsequent filings or broker notices may provide execution details.

Key Figures

Proposed resale: 21,676 shares Prior sale: 74,763 shares

2 metrics

Proposed resale 21,676 shares RSU vesting on 06/20/2026

Prior sale 74,763 shares Sold on 04/20/2026 by Jeffry Keyes

Key Terms

Restricted Stock Unit (RSU), Form 144, Rule 144 notice

3 terms

Restricted Stock Unit (RSU) financial

"Restricted Stock Unit Vesting | Quantum-Si Incorporated"

A restricted stock unit (RSU) is a promise from a company to give an employee company shares (or cash equal to their value) at a future date if certain conditions are met, such as staying with the company or hitting performance targets. For investors, RSUs matter because when they convert into actual shares they increase the number of shares available and can create selling pressure as employees cash out—think of them as a future paycheck paid in company stock.

Form 144 regulatory

"Filer Information | 144: Filer Information"

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.

Rule 144 notice regulatory

"Securities To Be Sold | Restricted Stock Unit Vesting"

A Rule 144 notice is a public filing that an insider or holder of restricted stock submits when they plan to sell shares that aren’t freely tradable yet; it lists how many shares they intend to sell and under what conditions. For investors, it matters because it signals potential insider selling and an upcoming increase in shares available to the market—similar to someone announcing a big garage sale, which can affect supply and price expectations.

FAQ

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

What does Quantum-Si's (QSI) Form 144 notice mean?

It signals a proposed resale of 21,676 Class A shares tied to RSU vesting on 06/20/2026. The notice notifies brokers and the SEC of an intended sale under resale rules; execution details are not included in the excerpt.

Who reported prior sales for QSI in the filing?

The filing shows a prior sale by Jeffry Keyes of 74,763 shares on 04/20/2026. That earlier transaction is listed separately in the 'Securities Sold During The Past 3 Months' section.

Are the 21,676 shares newly issued or from compensation?

They are reported as resulting from Restricted Stock Unit vesting on 06/20/2026, which indicates they were issued as equity compensation for services rendered rather than newly authorized shares.

Does the Form 144 state how the shares will be sold?

No. The excerpt lists the proposed amount and vesting origin but does not specify the sale method or timing. Brokerage or subsequent SEC filings may disclose execution details.

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

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Accepted by SEC EDGAR 06/24/2026 - 08:03 PM 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	8233	7641.87	197822663	06/22/2026	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	06/20/2026	Restricted Stock Unit Vesting	Quantum-Si Incorporated			21676	06/20/2026	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
Jeffry Keyes c/o Morgan Stanley Smith Barney LLC 1 New York Plaza 38th Floor New York NY 10004	Class A Common Stock	04/20/2026	74763	74799.39

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	06/24/2026
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)