Institutional ownership · Form 13F
CSTM institutional ownership
CONSTELLIUM SE: reported institutional holdings as of 2026-06-30 (filed through 2026-08-31), aggregated by StockEyes from SEC Form 13F information tables. CSTM is one of 2732 tickers in the validated publication set. Mapping coverage in this publication set: 4562 of 6046 universe tickers have at least one validated CUSIP mapping (75.5%). Latest-quarter filed value resolved to any listed ticker: 77.3%; resolved to this universe: 77.2%.
CSTM: change since the prior quarter's filings
More managers reported a position, with the count rising from 309 in the quarter ended 2026-03-31 to 386 in the quarter ended 2026-06-30 (+77, 24.9%). Total reported shares fell to 119,247,650 (-5,066,200, 4.1%), against the direction of the manager count. Among the 25 managers listed as top holders in both quarters, the largest increases were MORGAN STANLEY (+2,987,201 shares) and AMERICAN CENTURY COMPANIES INC (+2,135,264 shares), among 11 managers who added shares, and the largest decreases were FMR LLC (-4,767,046 shares) and Bpifrance SA (-4,190,000 shares), among 14 managers who reduced shares. MARSHALL WACE, LLP (1,093,740 shares), Senator Investment Group LP (1,083,489 shares) and 3 more entered the listed top holders; BEACONLIGHT CAPITAL, LLC (1,171,812 shares in the prior quarter), Cannell & Spears LLC (909,200 shares in the prior quarter) and 3 more dropped out of the listed top holders.
New to 13F data? Read how to read a 13F filing, or see where institutions moved overall in the Smart Money Report.
Reported totals, quarter ended 2026-06-30
386 reporting managers held 119,247,650 shares, reported value $3,489,829,624 exactly as filed. Values are position values transcribed from the filings, not current market prices.
Reported quarter-over-quarter change (quarter ended 2026-03-31 to quarter ended 2026-06-30): reporting managers +77, reported shares -5,066,200 (-4.08%), reported value +24.62%. These changes compare two filing snapshots.
Shares outstanding cross-check: no current issuer share-count point passed the freshness filter for this ticker, so the gate relied on holder-count and scale checks. See the hub methodology.
CSTM in this quarter's filings
Concentration check: the largest reported position, BlackRock, Inc. with 12,802,322 shares, is 10.7% of all shares reported for CSTM this quarter. The five largest reporting managers together account for 30.2% of the reported total, so the headline total is spread across a broad manager base rather than a few holders.
Reported quarter-over-quarter change: the reporting-manager count rose by 77 versus the quarter ended 2026-03-31, and reported shares moved -4.08% (-5,066,200 shares). That is a comparison of two filing snapshots, not a record of trades on any single day.
Shares-outstanding cross-check: no current issuer share-count point passed the freshness filter for CSTM, so the publication gate relied on holder-count scale, current-CUSIP validation, and quarter consistency for this ticker.
Largest reporting managers, CSTM
| # | Manager | Shares | Value as filed | Share of reported total |
|---|---|---|---|---|
| 1 | BlackRock, Inc. | 12,802,322 | $408,010,002 | 10.7% |
| 2 | Bpifrance SA | 8,403,903 | $267,832,389 | 7.0% |
| 3 | MORGAN STANLEY | 6,183,255 | $197,060,369 | 5.2% |
| 4 | VANGUARD PORTFOLIO MANAGEMENT LLC | 4,391,756 | $139,965,264 | 3.7% |
| 5 | AMERICAN CENTURY COMPANIES INC | 4,220,743 | $134,515,143 | 3.5% |
| 6 | STATE STREET CORP | 2,954,799 | $94,169,444 | 2.5% |
| 7 | ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | 2,844,747 | $90,662,087 | 2.4% |
| 8 | Nuveen, LLC | 2,770,828 | $88,306,289 | 2.3% |
| 9 | Kinetic Partners Management, LP | 2,542,400 | $81,026,288 | 2.1% |
| 10 | Encompass Capital Advisors LLC | 2,421,349 | $77,168,393 | 2.0% |
| 11 | AQR CAPITAL MANAGEMENT LLC | 2,402,937 | $76,581,596 | 2.0% |
| 12 | HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | 2,278,202 | $72,606,298 | 1.9% |
| 13 | D. E. Shaw & Co., Inc. | 2,198,618 | $70,069,955 | 1.8% |
| 14 | FMR LLC | 2,194,722 | $69,945,799 | 1.8% |
| 15 | GOLDMAN SACHS GROUP INC | 2,070,665 | $65,992,094 | 1.7% |
Manager names and figures are transcribed from each manager's own Form 13F information table. A manager listing shares in this snapshot does not mean it holds them today.
Reported change, 2026-03-31 to 2026-06-30
| Quarter ended | Filed through | Reporting managers | Reported shares | Value as filed |
|---|---|---|---|---|
| 2026-03-31 | 2026-05-29 | 309 | 124,313,850 | $2,800,301,128 |
| 2026-06-30 | 2026-08-31 | 386 | 119,247,650 | $3,489,829,624 |
Every change figure on this page is a reported quarter-over-quarter change between filing snapshots. It is not real-time trading activity.
CSTM reported totals over time
Quarter ended 2026-06-30: 386 reporting managers · 119,247,650 reported shares · $3,489,829,624 value as filed.
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Quarter-end 13F filed data, long positions only; filings arrive up to 45 days after quarter end.
CUSIPs behind the CSTM total
The validated bridge mapped 1 current CUSIP(s) to CSTM for this quarter: F21107101. Option pseudo-CUSIPs, units, warrants, and preferred classes are excluded from these common-share totals. Mapping coverage in this publication set: 4562 of 6046 universe tickers have at least one validated CUSIP mapping (75.5%). Latest-quarter filed value resolved to any listed ticker: 77.3%; resolved to this universe: 77.2%.
What this page is and is not
Form 13F reports are quarterly holdings snapshots. Managers file up to about 45 days after quarter-end, so these figures describe reported positions as of the quarter-end date, not holdings today. 13F lists reportable long positions from managers above the SEC reporting threshold and omits short positions entirely.
This page is informational only. It is not investment advice, a recommendation, or a signal to buy or sell. Source: SEC Form 13F bulk data set for filings through 2026-08-31 (period ended 2026-06-30), joined to tickers through StockEyes' validated CUSIP bridge. Methodology and coverage are documented on the institutional ownership hub.
Insider transactions for CSTM (officer and director buys and sells) are covered by InsiderTrace: insidertrace.com/stock/cstm. StockEyes does not duplicate insider transaction tables.
Related StockEyes pages
Latest headlines tagged CSTM are on the market news wire. Upcoming earnings and market dates are on the events calendar. The term itself is defined in the institutional investor glossary entry, and the research workflow behind pages like this one is walked through in how to research a stock and how to compare SEC filings.