Constellium SE (CSTM) Ownership
CSTM ownership summary
as of October 18, 2026- Institutions
- 92.3% of shares outstanding
- Insiders
- 3.02% of shares outstanding
- Shares outstanding
- 135.5M
- Float
- 123.4M shares available to trade
- Short interest
- 4.67% 6.3M shares short
- Days to cover
- 3.99 short interest down 9.8% vs prior month
- Institutions 92.27%
- Insiders 3.02%
- Other investors 4.72%
CSTM top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 9.45% | 12.8M | $326.1M | −161,881 (−1.2%) | June 30, 2026 |
| 2 | Bpifrance SA | 6.20% | 8.4M | $214.0M | −4.2M (−33.3%) | June 30, 2026 |
| 3 | Morgan Stanley - Brokerage Accounts | 4.56% | 6.2M | $157.5M | +3.0M (+93.5%) | June 30, 2026 |
| 4 | Vanguard Portfolio Management, LLC | 3.24% | 4.4M | $111.9M | +464,659 (+11.8%) | June 30, 2026 |
| 5 | American Century Companies Inc | 3.11% | 4.2M | $107.5M | +2.1M (+102.4%) | June 30, 2026 |
| 6 | T. Rowe Price Investment Management,Inc. | 2.20% | 3.0M | $75.9M | −980,253 (−24.7%) | June 30, 2026 |
| 7 | State Street Corp | 2.18% | 3.0M | $75.3M | +191,304 (+6.9%) | June 30, 2026 |
| 8 | Arrowstreet Capital Limited Partnership | 2.10% | 2.8M | $72.5M | −383,280 (−11.9%) | June 30, 2026 |
| 9 | Nuveen, LLC | 2.04% | 2.8M | $70.6M | −56,903 (−2.0%) | June 30, 2026 |
| 10 | Kinetic Partners Management LP | 1.88% | 2.5M | $64.8M | +1.2M (+93.7%) | June 30, 2026 |
| 11 | Encompass Capital Advisors LLC | 1.79% | 2.4M | $61.7M | −55,929 (−2.3%) | June 30, 2026 |
| 12 | AQR Capital Management LLC | 1.77% | 2.4M | $61.2M | +328,076 (+15.8%) | June 30, 2026 |
| 13 | HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | 1.68% | 2.3M | $58.0M | +221,866 (+10.8%) | June 30, 2026 |
| 14 | D. E. Shaw & Co LP | 1.62% | 2.2M | $56.0M | −1.0M (−32.0%) | June 30, 2026 |
| 15 | FMR Inc | 1.62% | 2.2M | $55.9M | −4.8M (−68.5%) | June 30, 2026 |
| 16 | AllianceBernstein L.P. | 1.60% | 2.2M | $55.1M | −154,777 (−6.7%) | June 30, 2026 |
| 17 | Acadian Asset Management LLC | 1.55% | 2.1M | $53.7M | +834,642 (+65.6%) | June 30, 2026 |
| 18 | The Goldman Sachs Group Inc | 1.53% | 2.1M | $52.7M | +698,889 (+50.9%) | June 30, 2026 |
| 19 | Millennium Management LLC | 1.44% | 2.0M | $49.8M | −1.5M (−43.6%) | June 30, 2026 |
| 20 | Brightline Capital Management LLC | 1.42% | 1.9M | $49.0M | +76,000 (+4.1%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 10 holders added 9.2M shares and 10 cut 13.3M.
CSTM top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | iShares Russell 2000 ETF | 2.44% | 3.3M | $84.1M | −38,016 (−1.1%) | September 30, 2026 |
| 2 | Avantis International Small Cap Val ETF | 1.90% | 2.6M | $65.7M | — | September 30, 2026 |
| 3 | Fidelity Small Cap Index | 1.09% | 1.5M | $37.7M | +12,876 (+0.9%) | July 31, 2026 |
| 4 | Vanguard Strategic Equity Inv | 0.95% | 1.3M | $32.7M | +202,441 (+18.7%) | June 30, 2026 |
| 5 | Nomura Small Cap Value A | 0.89% | 1.2M | $30.6M | — | August 31, 2026 |
| 6 | iShares Russell 2000 Growth ETF | 0.88% | 1.2M | $30.2M | −1,502 (−0.1%) | September 30, 2026 |
| 7 | American Century Small Cap Growth Inv | 0.81% | 1.1M | $28.1M | −13,605 (−1.2%) | September 30, 2026 |
| 8 | CREF Total Global Stock Account R3 | 0.72% | 970K | $24.7M | −84,577 (−8.0%) | August 31, 2026 |
| 9 | BlackRock High Yield K | 0.70% | 951K | $24.2M | — | August 31, 2026 |
| 10 | AB Small Cap Growth A | 0.69% | 934K | $23.8M | −14,587 (−1.5%) | August 31, 2026 |
| 11 | Vanguard Explorer Inv | 0.63% | 856K | $21.8M | +84,619 (+11.0%) | June 30, 2026 |
| 12 | BlackRock Advantage Small Cap Core Instl | 0.61% | 832K | $21.2M | +49,104 (+6.3%) | August 31, 2026 |
| 13 | Vanguard Russell 2000 ETF | 0.54% | 738K | $18.8M | −41,242 (−5.3%) | September 30, 2026 |
| 14 | Nuveen Quant Small Cap Equity R6 | 0.50% | 675K | $17.2M | — | August 31, 2026 |
| 15 | Nomura VIP Small Cap Value Series Std | 0.46% | 628K | $16.0M | — | August 31, 2026 |
| 16 | T. Rowe Price Small-Cap Value | 0.41% | 559K | $14.2M | — | September 30, 2026 |
| 17 | Fidelity US All Cap Series F | 0.40% | 537K | $13.7M | −62,200 (−10.4%) | March 31, 2026 |
| 18 | Vanguard Strategic Small-Cap Equity Inv | 0.38% | 513K | $13.1M | — | June 30, 2026 |
| 19 | Fidelity Stock Selector Small Cap | 0.35% | 475K | $12.1M | — | July 31, 2026 |
| 20 | American Beacon Small Cp Val R5 | 0.35% | 471K | $12.0M | +118,447 (+33.6%) | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
CSTM insider transactions
latest 14| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-03-10 | Ingrid Joerg | Sell | $25.87 | 4,614 | $119,364 |
| 2026-03-10 | Jack Q Guo | Sell | $25.87 | 41,717 | $1.1M |
| 2026-03-10 | Marcus Becker | Sell | $25.87 | 1,113 | $28,793 |
| 2026-03-10 | Philip Ryan Jurkovic | Sell | $25.87 | 29,900 | $773,513 |
| 2026-03-10 | Philippe Hoffmann | Sell | $25.87 | 4,728 | $122,313 |
| 2026-03-10 | Stephane Corre | Sell | $25.89 | 1,500 | $38,835 |
| 2026-03-09 | Nicolas Brun | Sell | $24.67 | 17,701 | $436,684 |
| 2026-03-04 | Philippe Hoffmann | Sell | $26.45 | 80,000 | $2.1M |
| 2026-03-02 | Jean-Christophe Deslarzes | Buy | $24.77 | 1,665 | $41,242 |
| 2026-02-27 | Stephane Corre | Sell | $24.69 | 3,000 | $74,070 |
| 2026-02-26 | Isabelle Boccon-Gibod | Sell | $25.77 | 10,000 | $257,700 |
| 2026-02-25 | Stephane Corre | Sell | $25.71 | 3,200 | $82,272 |
| 2026-02-23 | Stephen Charles Walters | Sell | $25.39 | 1,500 | $38,085 |
| 2026-02-20 | Marcus Becker | Sell | $25.58 | 15,570 | $398,281 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
CSTM shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns CSTM
Institutional investors own 92.3% of Constellium's shares and insiders 3.02%. The largest holder is BlackRock Inc with 9.45% of the shares (12.8M), as of June 30, 2026. Among the top 20 institutions, 10 added shares and 10 reduced their stake in the latest filings. Short interest is 4.67% of the float, or 3.99 days of average trading volume. The share count rose 40.3% since 2014.
Related: CSTM analyst forecast, CSTM key metrics. See the CSTM stock overview for the latest quote and news.
CSTM ownership FAQ
Who owns the most Constellium stock?
The largest shareholders of Constellium are BlackRock Inc (9.45%), Bpifrance SA (6.20%), Morgan Stanley - Brokerage Accounts (4.56%), Vanguard Portfolio Management, LLC (3.24%), American Century Companies Inc (3.11%).
What percentage of Constellium is owned by institutions?
Institutions hold 92.3% of Constellium's shares outstanding; insiders hold 3.02%.
Which funds own Constellium?
The largest fund holders of Constellium are iShares Russell 2000 ETF (2.44%), Avantis International Small Cap Val ETF (1.90%), Fidelity Small Cap Index (1.09%), Vanguard Strategic Equity Inv (0.95%), Nomura Small Cap Value A (0.89%).
What is Constellium's short interest?
6.3M shares of Constellium were sold short, 4.67% of the float; at the average daily volume it would take 3.99 days to cover.
Are insiders buying or selling Constellium?
Of the latest 14 reported insider transactions in Constellium (since February 20, 2026), 1 were purchases and 13 were sales.
How many shares of Constellium are outstanding?
Constellium has 135.5M shares outstanding, of which 123.4M are in the public float.