Constellium SE
Constellium SE (CSTM) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · CSTM · as of Sep 30, 2025
Ownership Breakdown
249
Institutional Holders
▲ 14 vs Q2
$1.89B
Total Inst. Value
▲ $145.02M vs Q2
136.15M
Shares Outstanding
freeFloat 91.15%
127.23M
13F Shares Held
▼ 4.20M vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
CSTM largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
BLACKROCK, INC. secondary smelting & refining of nonferrous metals | 14.02M | 9.96% | 9.96% | $208.61B | Nov 12, 2025 | ▲ 162.5K |
FMR LLC secondary smelting & refining of nonferrous metals | 13.52M | 9.60% | 9.60% | $201.15B | Nov 13, 2025 | ▼ 295.1K |
BPIFRANCE SA secondary smelting & refining of nonferrous metals | 12.59M | 8.94% | 8.94% | $187.40B | Nov 3, 2025 | — held |
MILLENNIUM MANAGEMENT LLC secondary smelting & refining of nonferrous metals | 6.94M | 4.93% | 4.93% | $103.20B | Nov 14, 2025 | ▲ 1.81M |
NUT TREE CAPITAL MANAGEMENT, LP secondary smelting & refining of nonferrous metals | 5.21M | 3.70% | 3.70% | $77.58B | Nov 14, 2025 | ▼ 442.0K |
T. ROWE PRICE INVESTMENT MANAGEMENT, INC. secondary smelting & refining of nonferrous metals | 5.12M | 3.63% | 3.63% | $76.14B | Nov 14, 2025 | ▼ 9.19M |
ENCOMPASS CAPITAL ADVISORS LLC secondary smelting & refining of nonferrous metals | 4.26M | 3.03% | 3.03% | $63.45B | Nov 14, 2025 | ▼ 1.10M |
VANGUARD GROUP INC secondary smelting & refining of nonferrous metals | 3.30M | 2.34% | 2.34% | $49.09B | Nov 7, 2025 | ▲ 938.2K |
NUVEEN, LLC secondary smelting & refining of nonferrous metals | 2.85M | 2.02% | 2.02% | $42.41B | Nov 12, 2025 | ▲ 709.3K |
STATE STREET CORP secondary smelting & refining of nonferrous metals | 2.57M | 1.82% | 1.82% | $38.21B | Nov 14, 2025 | ▲ 64.9K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
29
Increased
+9.87M shares0
New Positions
first time holders19
Decreased
−13.24M shares0
Sold Out
fully exitedNet shares change (top 50)
3.36M
+9.87M / −13.24M
Net new holders
+10
0 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
CSTM insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
1
Buy transactions
8
Sell transactions
0.13
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Ormerod John director | Jun 4, 2026 | Sale | 8,000 | $35.01 | $280.1K | 24.9K | Form 4 ↗ |
Becker Marcus SVP CPO | May 28, 2026 | Sale | 10,391 | $34.93 | $363.0K | 16.8K | Form 4 ↗ |
Soultz Bradley Lee director | May 14, 2026 | Purchase | 2,500 | $33.84 | $84.6K | 2.5K | Form 4 ↗ |
Jarrett Martin SVP Chief Innovation Officer | May 14, 2026 | Sale | 4,716 | $33.46 | $157.8K | 15.4K | Form 4 ↗ |
Piquier Ludovic SVP Manuf Excellence & CTO | May 12, 2026 | Sale | 1,000 | $33.57 | $33.6K | 241.7K | Form 4 ↗ |
Brun Nicolas SVP PA, Comm & Sust | May 11, 2026 | Sale | 26,661 | $33.85 | $902.5K | 104.9K | Form 4 ↗ |
Corre Stephane President, AS&I | May 8, 2026 | Sale | 5,000 | $33.52 | $167.6K | 62.3K | Form 4 ↗ |
Brandjes Michiel director | May 5, 2026 | Sale | 10,400 | $31.25 | $325.0K | 41.6K | Form 4 ↗ |
Guo Jack Q. EVP & CFO | May 5, 2026 | Sale | 25,201 | $32.62 | $822.1K | 185.4K | Form 4 ↗ |
Hoffmann Philippe President, A&T | May 1, 2026 | Sale | 50,000 | $31.92 | $1.60M | 144.2K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Constellium SE (CSTM) is primarily owned by institutional investors, who hold approximately 93.5% of total shares outstanding. Company insiders own approximately 8.85%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of Constellium SE is BLACKROCK, INC., holding approximately 14.02 million shares — equal to 9.96% of outstanding shares — as of September 30, 2025.
A total of 249 institutional investors currently hold CSTM stock, with a combined institutional value of approximately $1.89 billion as of the most recent 13F filing period.
Frequently asked questions
CSTM ownershipConstellium SE (CSTM) is primarily owned by institutional investors, who hold approximately 93.5% of shares. The largest shareholder is BLACKROCK, INC. with a 9.96% stake. Company insiders hold 8.85%. Data sourced from SEC Form 13F as of September 30, 2025.