Constellium SE (NYSE: CSTM) Form 144 — 26,661 shares via JPM

Rhea-AI Filing Summary

Constellium SE filed a Form 144 notice for the proposed sale of 26,661 shares of Common Stock through J.P. Morgan Securities LLC on or about 05/11/2026 on the NYSE. The filing lists prior insider activity: 17,701 shares were sold on 03/09/2026 for $436,679.21. The notice also records equity awards issued on 05/25/2021 of 5,814 RSUs and 20,847 PSUs.

Insights

Securities Counsel

Form 144 notice records a proposed resale of company common stock by an affiliate.

The filing shows a broker-dealer, J.P. Morgan Securities LLC, named for the proposed transaction and an indicated quantity of 26,661 shares with an NYSE execution reference dated 05/11/2026. The excerpt also discloses recent sales of 17,701 shares on 03/09/2026.

Timing and final sale proceeds depend on execution; this notice itself is administrative and does not confirm completed sales. Subsequent transaction filings or broker confirmations would show final execution details.

Key Figures

Proposed shares to sell: 26,661 shares Dollar amount referenced: $902,558.99 Shares sold in past 3 months: 17,701 shares +3 more

6 metrics

Proposed shares to sell 26,661 shares Form 144 notice with NYSE reference dated <date>05/11/2026</date>

Dollar amount referenced $902,558.99 Line item adjacent to broker/dealer listing in the excerpt dated <date>05/11/2026</date>

Shares sold in past 3 months 17,701 shares Sale on <date>03/09/2026</date> by Nicolas Brun

Proceeds from past sale $436,679.21 Proceeds reported for the 03/09/2026 sale of 17,701 shares

RSUs issued 5,814 RSUs Equity compensation grant dated <date>05/25/2021</date>

PSUs issued 20,847 PSUs Equity compensation grant dated <date>05/25/2021</date>

Key Terms

Form 144, RSU, PSU, J.P. Morgan Securities LLC

4 terms

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.

RSU financial

"RSU Issuance | Constellium SE (issuer) | 5,814 | 05/25/2021"

Restricted stock units (RSUs) are a form of company shares given to employees as part of their compensation, usually with certain restrictions or conditions, such as remaining with the company for a set period. When these restrictions lift, employees receive actual shares that they can sell or hold. For investors, RSUs can impact a company's stock supply and reflect the company's commitment to attracting and retaining talent.

PSU financial

"PSU Issuance | Constellium SE (issuer) | 20,847 | 05/25/2021"

A PSU is a company where the government owns a controlling stake and often plays a direct role in its management and strategy. Think of it like a business that operates with public oversight, similar to a town-run utility versus a private neighborhood service. Investors watch PSUs differently because government involvement can affect profits, dividend policies, regulatory treatment and stability, so these stocks may behave more like policy instruments than pure market-driven enterprises.

J.P. Morgan Securities LLC market

"Common Stock | J.P. Morgan Securities LLC 270 Park Ave 10th Floor New York NY 10017"

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	26661	902558.99	135069771	05/11/2026	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	05/25/2021	RSU Issuance	Constellium SE (issuer)			5814	05/25/2021	Equity Compensation
Common Stock	05/25/2021	PSU Issuance	Constellium SE (issuer)			20847	05/25/2021	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
Nicolas Brun 2, rue de Gournay Oinville sur Montcient I0 78250	Class A Common	03/09/2026	17701	436679.21

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's (CSTM) Form 144 report?

It reports a proposed resale of 26,661 shares of Common Stock through J.P. Morgan Securities LLC with an NYSE reference dated 05/11/2026. The filing shows prior insider sales of 17,701 shares on 03/09/2026.

Who is the selling party listed in the CSTM Form 144?

The filing identifies broker-dealer J.P. Morgan Securities LLC as the named broker for the proposed sale and lists an individual, Nicolas Brun, in the recent sales section, showing activity tied to Class A Common shares.

Does the Form 144 confirm the sale of the 26,661 shares?

No; the Form 144 provides a notice of a proposed resale of 26,661 shares dated 05/11/2026. It does not by itself confirm execution or final proceeds; execution would be reported separately if completed.

What recent insider sales are disclosed for CSTM in this excerpt?

The excerpt records a prior sale of 17,701 shares of Class A Common on 03/09/2026 with proceeds of $436,679.21, shown under "Securities Sold During The Past 3 Months."

Are equity awards referenced in the filing relevant to the resale?

The filing lists equity awards issued on 05/25/2021: 5,814 RSUs and 20,847 PSUs. These appear as grant history; their inclusion does not itself state whether they are the specific shares being resold.