Constellium (NYSE: CSTM) director sells 10,400 shares, holds 41,600

Rhea-AI Filing Summary

Constellium SE director Michiel Brandjes sold ordinary shares in an open-market transaction. On the reported date, he sold 10,400 ordinary shares at a weighted-average price of $31.25 per share, with individual trade prices ranging from $31.00 to $33.00. Following this sale, he directly holds 41,600 ordinary shares.

Insider Trade Summary

Net Seller: 10,400 shares ($325,000)

Net Sell 1 txn

Insider Brandjes Michiel

Role null

Sold 10,400 shs ($325K)

Type	Security	Shares	Price	Value
Sale	Ordinary shares	10,400	$31.25	$325K

Holdings After Transaction: Ordinary shares — 41,600 shares (Direct, null)

Footnotes (1)

1. [object Object]

Key Figures

Shares sold: 10,400 shares Weighted-average sale price: $31.25 per share Trade price range: $31.00–$33.00 per share +2 more

5 metrics

Shares sold 10,400 shares Ordinary shares sold in open-market transaction

Weighted-average sale price $31.25 per share Average price for 10,400 shares sold

Trade price range $31.00–$33.00 per share Range of prices across multiple sale transactions

Shares owned after sale 41,600 shares Direct ownership of ordinary shares post-transaction

Net share direction -10,400 shares Net sell direction from transaction summary

Key Terms

open-market sale, Ordinary shares, weighted average price, Form 4, +1 more

5 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.

Ordinary shares financial

"security_title": "Ordinary shares""

Ordinary shares are a type of ownership stake in a company, giving shareholders a right to participate in the company’s profits and decision-making through voting. They are similar to owning a piece of a business, and their value can rise or fall based on the company's performance. Investors buy ordinary shares to potentially earn dividends and benefit from the company's growth over time.

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.

Form 4 regulatory

"INSIDER FILING DATA (Form 4):"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

transaction code "S" regulatory

"transaction_code_description": "Sale in open market or private transaction""

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^*

Brandjes Michiel

(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)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

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

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	05/05/2026		S		10,400	D	$31.25(1)	41,600	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 $31.00 to $33.00, 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 Michiel Brandjes	05/07/2026
	** 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 insider transaction did Constellium (CSTM) report on this Form 4?

Constellium reported that director Michiel Brandjesopen-market sale

How many Constellium (CSTM) shares did Michiel Brandjes sell and at what price?

Michiel Brandjes sold 10,400 ordinary sharesweighted-average price of $31.25$31.00 and $33.00, inclusive, across multiple transactions.

How many Constellium (CSTM) shares does Michiel Brandjes own after this sale?

After the reported transaction, Michiel Brandjes directly owns 41,600 ordinary sharespost-transaction

Was the Constellium (CSTM) insider transaction an open-market sale or another type?

The transaction is identified as an open-market sale

What does the weighted-average price mean in this Constellium (CSTM) Form 4?

The filing reports a weighted-average price$31.25$31.00 to $33.00, and detailed trade-by-trade data is available on request.