Constellium (CSTM) SVP Nicolas Brun sells 26,661 shares in open-market trade

Rhea-AI Filing Summary

Constellium SE senior vice president Nicolas Brun reported an open-market sale of ordinary shares. On May 11, 2026, he sold 26,661 ordinary shares of Constellium at a weighted average price of $33.85 per share across multiple trades between $33.79 and $34.04. After this transaction, Brun directly holds 104,891 ordinary shares of Constellium.

Insider Trade Summary

Net Seller: 26,661 shares ($902,475)

Net Sell 1 txn

Insider Brun Nicolas

Role SVP PA, Comm & Sust

Sold 26,661 shs ($902K)

Type	Security	Shares	Price	Value
Sale	Ordinary shares	26,661	$33.85	$902K

Holdings After Transaction: Ordinary shares — 104,891 shares (Direct, null)

Footnotes (1)

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Key Figures

Shares sold: 26,661 shares Weighted average sale price: $33.85 per share Price range of sales: $33.79–$34.04 per share +1 more

4 metrics

Shares sold 26,661 shares Open-market sale of Constellium ordinary shares on May 11, 2026

Weighted average sale price $33.85 per share Average price for 26,661 shares sold

Price range of sales $33.79–$34.04 per share Range of execution prices for multiple sale transactions

Shares held after transaction 104,891 shares Directly owned Constellium ordinary shares post-transaction

Key Terms

open-market sale, weighted average price, Securities and Exchange Commission

3 terms

open-market sale financial

"transaction_action": "open-market sale""

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

weighted average price financial

"The price reported is a weighted average price."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

Securities and Exchange Commission regulatory

"staff of the Securities and Exchange Commission, upon request"

A national government agency that enforces rules for buying, selling and disclosing information about stocks and other investments, acting like a referee and scorekeeper for financial markets. It requires companies to share clear, regular financial and business information and investigates fraud or rule-breaking, which matters to investors because those rules and disclosures help ensure fair prices, reduce hidden risks and make it easier to compare investment choices.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Brun Nicolas

(Last) (First) (Middle)

300 EAST LOMBARD STREET

SUITE 1710

(Street)

BALTIMORE MARYLAND 21202

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
CONSTELLIUM SE [ CSTM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	SVP PA, Comm & Sust

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/11/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Ordinary shares	05/11/2026		S		26,661	D	$33.85(1)	104,891	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $33.79 to $34.04, inclusive. The reporting person undertakes to provide to Constellium SE, any security holder of Constellium SE, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth herein.

Remarks:

	/s/ Kristine Carpenter, Attorney-in-Fact for Nicolas Brun	05/12/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What did Constellium (CSTM) executive Nicolas Brun report in his latest Form 4?

Nicolas Brun, a senior vice president at Constellium, reported selling 26,661 ordinary shares in an open-market transaction at a weighted average price of $33.85 per share. Following the sale, he directly holds 104,891 Constellium ordinary shares.

How many Constellium (CSTM) shares did Nicolas Brun sell and at what price?

Nicolas Brun sold 26,661 Constellium ordinary shares in an open-market sale. The weighted average sale price was $33.85 per share, with individual trades executed between $33.79 and $34.04 per share, according to the Form 4 footnote.

How many Constellium (CSTM) shares does Nicolas Brun hold after the reported sale?

After the reported open-market sale, Nicolas Brun directly holds 104,891 Constellium ordinary shares. This post-transaction holding is disclosed in the Form 4 as the total number of non-derivative shares beneficially owned following the transaction.

What does the weighted average price mean in Nicolas Brun’s Constellium (CSTM) share sale?

The weighted average price of $33.85 means Brun’s 26,661 sold shares were executed in multiple trades at prices between $33.79 and $34.04. The reported average reflects the overall price received across those separate transactions, as detailed in the Form 4 footnote.

Was Nicolas Brun’s Constellium (CSTM) transaction a market purchase or a sale?

The transaction was a sale. The Form 4 lists transaction code “S” and describes it as an open-market sale of 26,661 ordinary shares, rather than a purchase or option exercise, with the shares sold at a weighted average price of $33.85.