Isabelle Boccon-Gibod - 26 Feb 2026 Form 4 Insider Report for CONSTELLIUM SE (CSTM)

Role: Director
Signature: /s/ Kristine Carpenter, Attorney-in-Fact for Isabelle Boccon-Gibod
Issuer symbol: CSTM
Transactions as of: 26 Feb 2026
Net transactions value: -$257,700
Form type: 4
Filing time: 27 Feb 2026, 09:12:31 UTC
Previous filing: 02 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Boccon-Gibod Isabelle	Director	300 EAST LOMBARD STREET, SUITE 1710, BALTIMORE	/s/ Kristine Carpenter, Attorney-in-Fact for Isabelle Boccon-Gibod	27 Feb 2026	0002092744

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CSTM	Ordinary shares	Sale	$257,700	-10,000	-30%	$25.77	23,000	26 Feb 2026	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.77, to $25.77, 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.

Content

The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.77, to $25.77, 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.