Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
1,424 institutional managers reported holding STX for the quarter ended Mar 31, 2026. Together they hold about 78% of shares outstanding; the top 10 hold 42%. 288 opened new positions; 123 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| Vanguard Group | 27.45M | 11.99% | $10.76B | trimmed -2.5% | ≤2013 |
| BlackRock | 14.27M | 6.23% | $5.59B | trimmed -11.4% | ≤2013 |
| Sanders Capital, LLC (focused) | 12.90M | 5.63% | $5.05B | trimmed -24.9% | 2021 Q3 |
| State Street | 9.32M | 4.07% | $3.65B | trimmed -0.5% | ≤2013 |
| FMR (Fidelity) | 8.18M | 3.57% | $3.20B | added +117.5% | ≤2013 |
| Capital Research Global Investors | 5.74M | 2.50% | $2.25B | added +27.1% | 2023 Q3 |
| Geode Capital | 5.06M | 2.21% | $1.98B | added +3.3% | ≤2013 |
| Morgan Stanley | 4.76M | 2.08% | $1.86B | trimmed -10.5% | ≤2013 |
| WCM Investment Management | 4.35M | 1.90% | $1.70B | trimmed -15.7% | 2025 Q3 |
| DZ Bank AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main | 3.62M | 1.58% | $1.42B | trimmed -33.2% | 2025 Q3 |
| Goldman Sachs | 3.57M | 1.56% | $1.40B | added +29.7% | ≤2013 |
| Franklin Resources | 3.52M | 1.54% | $1.38B | trimmed -12.6% | ≤2013 |
| Bank OF America CORP /DE/ | 3.38M | 1.48% | $1.32B | trimmed -21% | ≤2013 |
| Invesco | 2.60M | 1.14% | $1.02B | added +1.6% | ≤2013 |
| MFS Investment Management | 2.54M | 1.11% | $993.6M | added +26.3% | 2025 Q3 |
| UBS | 2.17M | 0.95% | $848.9M | added +6.3% | ≤2013 |
| Northern Trust | 1.90M | 0.83% | $743.2M | unchanged | ≤2013 |
| Nomura Asset Management International INC. | 1.87M | 0.82% | $734.1M | added +2955.1% | 2024 Q2 |
| Deutsche Bank AG\ | 1.76M | 0.77% | $689.2M | added +10% | 2022 Q2 |
| Legal & General Group PLC | 1.51M | 0.66% | $593.4M | trimmed -0.6% | 2016 Q4 |
| Arrowstreet Capital | 1.43M | 0.63% | $561.6M | trimmed -55.1% | 2023 Q3 |
| Charles Schwab Investment Management | 1.36M | 0.60% | $534.7M | trimmed -0.9% | ≤2013 |
| D. E. Shaw | 1.29M | 0.56% | $505.2M | added +61.9% | 2014 Q4 |
| T. Rowe Price | 1.26M | 0.55% | $493.0M | added +8.2% | ≤2013 |
| Holocene Advisors | 1.09M | 0.47% | $426.1M | added +43.3% | 2020 Q1 |
| BNY Mellon | 1.06M | 0.46% | $414.6M | trimmed -14.8% | ≤2013 |
| BNP Paribas Financial Markets | 1.02M | 0.45% | $401.0M | added +14.2% | 2024 Q4 |
| Royal Bank OF Canada | 1.01M | 0.44% | $397.0M | trimmed -2% | ≤2013 |
| Bank OF Montreal /CAN/ | 1.01M | 0.44% | $395.1M | added +27% | ≤2013 |
| AQR Capital | 1.00M | 0.44% | $392.2M | added +17.4% | 2014 Q4 |
| Janus Henderson | 967.5k | 0.42% | $379.0M | added +3872.1% | ≤2013 |
| Russell Investments Group, LTD. | 966.5k | 0.42% | $378.6M | added +1% | 2016 Q4 |
| Amundi | 965.6k | 0.42% | $378.3M | added +32.2% | 2017 Q4 |
| Polar Capital Holdings PLC | 933.9k | 0.41% | $365.8M | trimmed -24% | 2025 Q2 |
| Value Aligned Research Advisors, LLC | 914.7k | 0.40% | $358.3M | added +624.3% | 2025 Q4 |
| CPP Investment Board | 883.6k | 0.39% | $346.1M | trimmed -2.8% | ≤2013 |
| Dimensional Fund Advisors | 836.0k | 0.36% | $327.5M | trimmed -7% | ≤2013 |
| National Pension Service | 827.8k | 0.36% | $324.3M | trimmed -17% | 2024 Q1 |
| Nuveen | 771.4k | 0.34% | $302.2M | trimmed -1.2% | ≤2013 |
| Atalan Capital Partners, LP (focused) | 718.8k | 0.31% | $281.6M | trimmed -3.7% | 2025 Q2 |
| Swedbank Robur | 709.2k | 0.31% | $277.8M | added +67.6% | 2021 Q1 |
| Barclays PLC | 669.8k | 0.29% | $262.4M | trimmed -14.1% | 2022 Q1 |
| Swiss National Bank | 639.4k | 0.28% | $250.5M | added +9.6% | ≤2013 |
| Mitsubishi UFJ Asset Management CO., LTD. | 622.3k | 0.27% | $243.8M | added +9.6% | ≤2013 |
| Acadian Asset Management | 604.9k | 0.26% | $237.0M | trimmed -9.8% | ≤2013 |
| Castle Hook Partners LP (focused) | 561.6k | 0.24% | $220.0M | trimmed -30% | 2025 Q2 |
| Point72 | 546.4k | 0.24% | $214.0M | added +37.4% | 2024 Q1 |
| First Trust Advisors LP | 536.7k | 0.23% | $210.2M | trimmed -4% | ≤2013 |
| Soroban Capital Partners LP (focused) | 534.4k | 0.23% | $209.3M | unchanged | 2025 Q1 |
| Maple Rock Capital Partners INC. (focused) | 534.0k | 0.23% | $209.2M | trimmed -19.8% | 2024 Q2 |
Largest 50 of 1,424 shown; the full ranked, searchable register is at boothcheck.com/holders/STX. 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.