Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
302 institutional managers reported holding CSTM for the quarter ended Mar 31, 2026. Together they hold about 89% of shares outstanding; the top 10 hold 41%. 77 opened new positions; 26 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| BlackRock | 12.96M | 9.26% | $318.6M | trimmed -5.6% | 2013 Q3 |
| Bpifrance SA (focused) | 12.59M | 8.99% | $309.5M | unchanged | 2018 Q4 |
| FMR (Fidelity) | 6.96M | 4.97% | $171.1M | trimmed -34.1% | 2018 Q1 |
| Vanguard Group | 4.26M | 3.04% | $104.8M | added +5.2% | 2015 Q1 |
| T. Rowe Price Investment Management, INC. | 3.96M | 2.83% | $97.3M | added +139.6% | 2022 Q3 |
| Millennium Management | 3.47M | 2.48% | $85.3M | trimmed -44.7% | ≤2013 |
| D. E. Shaw | 3.23M | 2.31% | $79.5M | added +5.9% | ≤2013 |
| Arrowstreet Capital | 3.23M | 2.30% | $79.3M | added +620.9% | 2024 Q4 |
| Morgan Stanley | 3.20M | 2.28% | $78.5M | trimmed -14.3% | ≤2013 |
| Nuveen | 2.83M | 2.02% | $69.5M | unchanged | 2021 Q2 |
| State Street | 2.76M | 1.97% | $67.9M | added +3.9% | 2014 Q1 |
| Encompass Capital Advisors LLC | 2.48M | 1.77% | $60.9M | trimmed -46.8% | 2024 Q1 |
| AllianceBernstein | 2.32M | 1.65% | $56.9M | added +1573.5% | 2016 Q3 |
| American Century Companies INC | 2.09M | 1.49% | $51.3M | added +15.1% | 2021 Q3 |
| AQR Capital | 2.07M | 1.48% | $51.0M | added +17.5% | 2022 Q1 |
| Healthcare OF Ontario Pension Plan Trust Fund | 2.06M | 1.47% | $50.5M | added +894.4% | 2021 Q2 |
| Nomura Asset Management International INC. | 1.91M | 1.37% | $47.0M | trimmed -1.6% | 2025 Q4 |
| Brightline Capital Management, LLC (focused) | 1.85M | 1.32% | $45.4M | unchanged | 2023 Q3 |
| Scopus Asset Management, L.p. | 1.68M | 1.20% | $41.3M | trimmed -2.9% | 2025 Q2 |
| Geode Capital | 1.67M | 1.19% | $41.0M | added +2.3% | 2021 Q2 |
| SG Americas Securities, LLC | 1.50M | 1.07% | $36.8M | added +53.6% | 2021 Q2 |
| Westwood Holdings Group INC | 1.40M | 1.00% | $34.4M | opened | 2026 Q1 |
| Goldman Sachs | 1.37M | 0.98% | $33.7M | unchanged | 2014 Q1 |
| UBS | 1.33M | 0.95% | $32.6M | trimmed -6.8% | ≤2013 |
| Kinetic Partners Management, LP (focused) | 1.31M | 0.94% | $32.3M | opened | 2026 Q1 |
| Acadian Asset Management | 1.27M | 0.91% | $31.3M | added +252% | 2023 Q3 |
| Beaconlight Capital, LLC (focused) | 1.17M | 0.84% | $28.8M | trimmed -12.5% | 2019 Q3 |
| Point72 | 1.01M | 0.72% | $24.7M | added +216% | 2023 Q4 |
| Northern Trust | 977.6k | 0.70% | $24.0M | added +3.8% | 2016 Q1 |
| William Blair Investment Management, LLC | 918.1k | 0.66% | $22.6M | opened | 2026 Q1 |
| Cannell & Spears LLC | 909.2k | 0.65% | $22.3M | trimmed -6% | 2024 Q1 |
| Allianz Asset Management GmbH | 893.9k | 0.64% | $22.0M | added +408.1% | 2025 Q3 |
| Engineers Gate Manager LP | 884.1k | 0.63% | $21.7M | trimmed -15.7% | 2024 Q1 |
| Bayberry Capital Partners LP (focused) | 874.0k | 0.62% | $21.5M | opened | 2026 Q1 |
| Bank OF America CORP /DE/ | 851.2k | 0.61% | $20.9M | added +100.1% | ≤2013 |
| Penn Capital Management Company, LLC | 844.9k | 0.60% | $20.8M | added +131.4% | 2025 Q4 |
| Jane Street | 832.5k | 0.59% | $20.5M | added +165.4% | 2020 Q1 |
| Soapstone Management L.p. (focused) | 800.0k | 0.57% | $19.7M | trimmed -40.7% | 2021 Q1 |
| Balyasny Asset Management | 795.4k | 0.57% | $19.5M | added +262.6% | 2025 Q4 |
| Charles Schwab Investment Management | 783.2k | 0.56% | $19.2M | trimmed -3.2% | 2018 Q2 |
| Citadel Advisors | 770.6k | 0.55% | $18.9M | added +504.4% | 2021 Q4 |
| Cooper Creek Partners Management LLC | 764.2k | 0.55% | $18.8M | trimmed -23.5% | 2024 Q4 |
| Panagora Asset Management INC | 704.8k | 0.50% | $17.3M | added +13.5% | 2021 Q2 |
| Mountaineer Partners Management, LLC (focused) | 658.5k | 0.47% | $16.2M | trimmed -3.4% | 2023 Q1 |
| Federated Hermes, INC. | 652.7k | 0.47% | $16.0M | added +119.7% | 2025 Q2 |
| NEW York State Common Retirement Fund | 570.2k | 0.41% | $14.0M | added +99.2% | 2021 Q2 |
| Fisher Investments | 539.5k | 0.39% | $13.3M | added +5202.8% | 2025 Q4 |
| HRT Financial LP | 518.8k | 0.37% | $12.8M | added +63.8% | 2024 Q3 |
| Bridgewater Associates | 503.0k | 0.36% | $12.4M | opened | 2026 Q1 |
| ArrowMark Colorado Holdings LLC | 497.4k | 0.35% | $12.2M | trimmed -17.6% | 2023 Q4 |
Largest 50 of 302 shown; the full ranked, searchable register is at boothcheck.com/holders/CSTM. Related filers are grouped using the filings' own included-manager declarations. Historically, several managers opening new positions in the same quarter said almost nothing about the quarter that followed (59,118 cases since 2013). A filed record, not a forecast. Nothing here is investment advice.