Constellium (NYSE: CSTM) SVP reports 121,167-share ownership stake

Rhea-AI Filing Summary

Constellium SE senior vice president Nicolas Brun filed an amended insider ownership report showing he holds 121,167 ordinary shares. This total consists of 99,893 ordinary shares held as of January 1, 2026 and 21,274 restricted stock units that are still subject to vesting and were previously omitted from his original ownership filing.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Brun Nicolas

Role SVP PA, Comm & Sust

Type	Security	Shares	Price	Value
holding	Ordinary shares	--	--	--

Holdings After Transaction: Ordinary shares — 121,167 shares (Direct)

Footnotes (1)

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Understanding Insider Trading Forms →

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

Brun Nicolas

(Last) (First) (Middle)

300 EAST LOMBARD STREET

SUITE 1710

(Street)

BALTIMORE MD 21202

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
01/01/2026

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

4. 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

5. If Amendment, Date of Original Filed (Month/Day/Year)
01/02/2026

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

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

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Ordinary shares	121,167(1)	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Amount consists of (i) 99,893 ordinary shares held by the Reporting Person as of January 1, 2026 and (ii) an aggregate of 21,274 restricted stock units which remain subject to vesting restrictions and which were inadvertently omitted from the Reporting Person's original Form 3 filing.

Remarks:

	/s/ Kristine Carpenter, Attorney-in-Fact for Nicolas Brun	03/11/2026
	** 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 5 (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.

FAQ

What does the ConstelLIUM (CSTM) Form 3/A filing report for Nicolas Brun?

The Form 3/A shows SVP Nicolas Brun reporting beneficial ownership of 121,167 ordinary shares. This reflects his current direct stake, including both outright share ownership and restricted stock units subject to vesting conditions as of January 1, 2026.

How many CONSTELLIUM (CSTM) ordinary shares does Nicolas Brun hold?

Nicolas Brun reports beneficial ownership of 121,167 ordinary shares. This includes 99,893 ordinary shares held directly and 21,274 restricted stock units that will convert into shares if vesting conditions are fully satisfied over time.

What are the 21,274 restricted stock units disclosed for CSTM insider Nicolas Brun?

The 21,274 restricted stock units represent share-based awards granted to Nicolas Brun that remain subject to vesting restrictions. They were inadvertently omitted from his original ownership report and are now included in his total reported stake of 121,167 ordinary shares.

Did Nicolas Brun buy or sell CONSTELLIUM (CSTM) shares in this Form 3/A?

The Form 3/A does not report any new share purchases or sales. It updates Nicolas Brun’s reported holdings to include 21,274 restricted stock units, correcting his original ownership filing without indicating a change in trading activity.

Why did CONSTELLIUM (CSTM) SVP Nicolas Brun amend his original Form 3?

The amendment was filed because 21,274 restricted stock units were inadvertently omitted from the original Form 3. The Form 3/A corrects this error by adding these awards to Brun’s disclosed beneficial ownership, bringing his total reported stake to 121,167 ordinary shares.