$CSTM

$24.56 +$0.00 (0.0%) After hours

$CSTM Overview Financial Statements SEC Filings Executives News Red Flags Capital Raising Ownership Insider Transactions Congressional Trades

Ownership

13F as of Q2 2026 · 135.5M shares outstanding

Who owns CSTM?

By type of holder

Institutions 88.3% Insiders 0.0% Everyone else 11.7%

Concentration Top 10 holders own 44.2%

BlackRock, Inc. 9.5% · Bpifrance SA 6.2%

Institutional ownership

88.3%

-3.4 pts vs last qtr

Institutional holders

385

+72 vs last qtr

Net shares bought

−4.7M

by institutions in Q2 2026

New / sold out

110 / 38

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

Morgan Stanley +3.0M
American Century Companies Inc +2.1M

Biggest sellers in Q2 2026

FMR LLC −4.8M
Bpifrance SA −4.2M

Who is planning to sell?

Notices of proposed sale, last 12 months

$81.4M

24 notices from 14 people

Shares covered

2.5M

1.85% of the company

Arranged in advance

of the value is under a 10b5-1 plan

Under a 10b5-1 plan No plan

Largest proposed sellers

Bpifrance Participations SA May be deemed an affiliate $69.6M
Philippe Hoffmann Affiliate $3.83M

Every notice on Red Flags →

A Form 144 is notice of a planned sale, not the sale itself. What insiders actually sold is on Insider Transactions.

Is your stake being diluted?

Diluted share count, FY2022–FY2025

−3.4%

−1.15% a year

Each share's claim on the business

+3.5%

grew without buying or selling a share

Spent on buybacks vs paid in stock

$194M vs —

over 4 fiscal years

Diluted shares, split-adjusted

Buybacks Stock-based comp

How patient are the owners?

Institutional shares by how long they've been held

5+ years40% 3–5 years19% 1–3 years21% Under 1 year21%

Quarterly turnover

18.4%

of institutional shares changed hands

Top 10 managers, median time held

4.8 years

Super Investors

Investment managers reporting CSTM on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
B BlackRock, Inc.	12.8M	9.45%	−161.9K (−1.2%)	≤2021	0.0%
Shares held by quarter Peak holding14.0M (Q3'25) Change over 8 quarters+362.3K Share of the company9.450% BlackRock, Inc.'s full portfolio →
BS Bpifrance SA 13D · 6.2%	8.4M	6.20%	−4.2M (−33.3%)	2021	19.7%
Shares held by quarter Peak holding12.6M (Q3'24) Change over 8 quarters−4.2M Share of the company6.200% Disclosed stake13D · 6.2% Bpifrance SA's full portfolio →

BlackRock, Inc.

12.8M

% of company

9.45%

Change vs last qtr

−161.9K (−1.2%)

Held since

≤2021

Bpifrance SA

13D · 6.2%

8.4M

% of company

6.20%

Change vs last qtr

−4.2M (−33.3%)

Held since

2021

28 more super investors behind a free account

See every manager holding Constellium SE, how their position has changed, and how long they've held it.

Institutional Funds

Mutual funds and ETFs reporting CSTM on Form N-PORT; together they hold 10.3% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
AI Avantis International Small Cap Value ETF American Century ETF Trust	$64.3M	1.9M	1.38%	0.32%	May 31, 2026
VS Vanguard Strategic Equity Fund Vanguard Horizon Funds	$38.6M	1.2M	0.89%	0.32%	June 30, 2026

Avantis International Small Cap Value ETF

American Century ETF Trust

Position value

$64.3M

% of company

1.38%

% of the fund

0.32%

As of

May 31, 2026

Vanguard Strategic Equity Fund

Vanguard Horizon Funds

Position value

$38.6M

% of company

0.89%

% of the fund

0.32%

As of

June 30, 2026

23 more funds behind a free account

See every fund holding Constellium SE and how much of the fund the position is.

Insiders and 5%+ holders

From Forms 3/4/5 and Schedules 13D/G

Holder	Shares	% of company	Change vs last qtr	8 quarters	Held since	% of their book
EB EPIC Bpifrance 5%+ holder 13D · 6.2%	8.4M	6.20%	—	—	—	—
This holder reports through Schedule 13D/G, not a quarterly 13F. Share of the company6.200% Disclosed stake13D · 6.2% View the 13D/G filing →
BP Bpifrance Participations S.A. 5%+ holder 13D · 6.2%	8.4M	6.20%	—	—	—	—
This holder reports through Schedule 13D/G, not a quarterly 13F. Share of the company6.200% Disclosed stake13D · 6.2% View the 13D/G filing →

EPIC Bpifrance

5%+ holder13D · 6.2%

8.4M

% of company

6.20%

Change vs last qtr

—

Held since

—

Bpifrance Participations S.A.

5%+ holder13D · 6.2%

8.4M

% of company

6.20%

Change vs last qtr

—

Held since

—

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