Constellium SE (CSTM) files Rule 144; insider sold 15,570 shares

Rhea-AI Filing Summary

Constellium SE submitted a Rule 144 notice reporting proposed sales of Common Stock related to equity compensation. The filing lists 14,592 shares from a PSU issuance and 6,912 shares from an RSU issuance, both dated 03/09/2026. The form also records a sale of 15,570 Class A shares by Marcus Becker on 02/20/2026 for $398,269.75.

Insights

Securities Compliance Analyst

Rule 144 notice lists equity-compensation shares and a recent insider sale.

The filing enumerates 14,592 shares tied to a PSU issuance and 6,912 tied to RSU vesting, both dated 03/09/2026. These entries reflect planned or reportable dispositions under Rule 144 rather than company financings.

Cash treatment and sale method are not specified in the excerpt; subsequent filings or broker confirmations could provide execution details.

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

144: Issuer Information

Name of Issuer

SEC File Number

Address of Issuer

Phone

Name of Person for Whose Account the Securities are To Be Sold

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

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
Common Stock	J.P. Morgan Securities LLC 270 Park Ave 10th Floor New York NY 10017	1113	28796.8	135069771	03/10/2026	NYSE

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 *
Common Stock	03/09/2026	PSU Issuance	Constellium SE (issuer)			14592	03/09/2026	Equity Compensation
Common Stock	03/09/2026	RSU Issuance	Constellium SE (issuer)			6912	03/09/2026	Equity Compensation

* 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
Marcus Becker Hirzlistrasse 17 Goldingen V8 8638	Class A Shares	02/20/2026	15570	398269.75

144: Remarks and Signature

Remarks

Date of Notice

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

ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)

FAQ

What does Constellium SE's Form 144 (CSTM) report?

It reports proposed sales of equity compensation shares and a recent individual sale. The form lists 14,592 PSU shares and 6,912 RSU shares dated 03/09/2026, plus a 15,570-share sale by Marcus Becker on 02/20/2026.

Who sold shares recently according to the Form 144 for CSTM?

The filing records a sale by Marcus Becker of 15,570 Class A shares on 02/20/2026. The reported proceeds for that sale are $398,269.75, as shown in the excerpt.

Are the PSU and RSU amounts in Constellium's Form 144 vested or issuances?

The excerpt labels the line items as a PSU Issuance of 14,592 shares and an RSU Issuance of 6,912, both dated 03/09/2026. It presents them as equity compensation-related entries.

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

The provided excerpt does not specify sale method or broker mechanics. It lists share counts and dates; transaction mechanics and timing are not detailed in the visible content.

Does the Form 144 show proceeds from the recent insider sale for CSTM?

Yes. The excerpt shows Marcus Becker's sale of 15,570 shares on 02/20/2026 with proceeds of $398,269.75 noted alongside that transaction.