Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
788 institutional managers reported holding MDB for the quarter ended Mar 31, 2026. Together they hold about 86% of shares outstanding; the top 10 hold 35%. 112 opened new positions; 220 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| Vanguard Group | 8.75M | 10.75% | $2.14B | added +1.1% | 2017 Q4 |
| BlackRock | 5.73M | 7.03% | $1.40B | trimmed -1.1% | 2017 Q4 |
| FMR (Fidelity) | 2.19M | 2.69% | $536.6M | trimmed -7.9% | 2017 Q4 |
| T. Rowe Price | 2.09M | 2.57% | $512.1M | added +12.2% | 2017 Q4 |
| DZ Bank AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main | 1.95M | 2.40% | $478.0M | added +64.6% | 2025 Q3 |
| State Street | 1.84M | 2.27% | $451.3M | added +2.6% | 2018 Q1 |
| UBS | 1.55M | 1.90% | $379.4M | trimmed -7.3% | 2017 Q4 |
| Geode Capital | 1.53M | 1.88% | $373.9M | added +5.8% | 2017 Q4 |
| AQR Capital | 1.31M | 1.61% | $321.1M | added +127.7% | 2019 Q2 |
| Artisan Partners | 1.23M | 1.51% | $300.3M | added +186.4% | 2025 Q3 |
| Morgan Stanley | 1.22M | 1.50% | $298.1M | trimmed -11.8% | 2017 Q4 |
| ValueAct (focused) | 1.04M | 1.27% | $254.0M | trimmed -26.2% | 2025 Q2 |
| Capital Group (American Funds) | 1.02M | 1.25% | $248.9M | added +3.8% | 2017 Q4 |
| Jericho Capital Asset Management L.p. (focused) | 996.5k | 1.22% | $243.9M | unchanged | 2025 Q1 |
| D. E. Shaw | 931.6k | 1.14% | $228.0M | trimmed -36.1% | 2018 Q2 |
| Wellington Management | 904.6k | 1.11% | $221.4M | added +310.7% | 2018 Q1 |
| Invesco | 903.9k | 1.11% | $221.2M | trimmed -15% | 2018 Q4 |
| MFS Investment Management | 891.7k | 1.09% | $218.2M | added +24.7% | 2025 Q1 |
| PRIMECAP Management | 842.7k | 1.03% | $206.2M | trimmed -0.7% | 2020 Q3 |
| BNP Paribas Financial Markets | 748.0k | 0.92% | $183.1M | added +26.6% | 2018 Q2 |
| Arrowstreet Capital | 672.2k | 0.83% | $164.5M | trimmed -49.7% | 2024 Q4 |
| T. Rowe Price Investment Management, INC. | 664.6k | 0.82% | $162.6M | added +75.5% | 2022 Q3 |
| Qube Research & Technologies LTD | 609.6k | 0.75% | $149.2M | added +105.9% | 2023 Q3 |
| Employees Provident Fund Board | 584.6k | 0.72% | $143.1M | added +20.6% | 2023 Q4 |
| Swedbank Robur | 580.7k | 0.71% | $142.1M | trimmed -20.4% | 2021 Q1 |
| Citadel Advisors | 557.1k | 0.68% | $136.3M | trimmed -35.4% | 2018 Q3 |
| Bank OF America CORP /DE/ | 555.3k | 0.68% | $135.9M | unchanged | 2017 Q4 |
| Harel Insurance Investments & Financial Services LTD. | 550.0k | 0.68% | $134.6M | added +55% | 2020 Q2 |
| Legal & General Group PLC | 537.6k | 0.66% | $131.6M | added +2.5% | 2019 Q1 |
| SRS Investment Management, LLC (focused) | 526.9k | 0.65% | $129.0M | unchanged | 2025 Q1 |
| Federated Hermes, INC. | 524.3k | 0.64% | $128.3M | trimmed -6.7% | 2025 Q1 |
| Northern Trust | 517.1k | 0.64% | $126.6M | added +1.3% | 2017 Q4 |
| Deutsche Bank AG\ | 480.3k | 0.59% | $117.5M | trimmed -16.7% | 2018 Q1 |
| Neuberger Berman Group LLC | 474.5k | 0.58% | $116.1M | added +507.1% | 2020 Q1 |
| Point72 | 474.4k | 0.58% | $116.1M | trimmed -33.5% | 2023 Q3 |
| Robeco Institutional Asset Management B.v. | 468.5k | 0.58% | $114.7M | added +35.6% | 2021 Q1 |
| FIL LTD | 464.4k | 0.57% | $113.7M | trimmed -2.7% | 2025 Q1 |
| Fred Alger Management, LLC | 438.6k | 0.54% | $107.3M | trimmed -21.9% | 2025 Q3 |
| BNY Mellon | 421.5k | 0.52% | $103.2M | trimmed -11.4% | 2017 Q4 |
| Goldman Sachs | 411.3k | 0.51% | $100.7M | trimmed -11.1% | 2017 Q4 |
| Charles Schwab Investment Management | 407.3k | 0.50% | $99.7M | added +5.6% | 2018 Q1 |
| Millennium Management | 399.3k | 0.49% | $97.7M | added +18.5% | 2017 Q4 |
| Pictet Asset Management Holding SA | 390.3k | 0.48% | $95.5M | added +33.1% | 2019 Q2 |
| 1832 Asset Management L.p. | 377.0k | 0.46% | $92.3M | trimmed -50% | 2020 Q3 |
| Amundi | 376.4k | 0.46% | $92.1M | added +17.8% | 2019 Q2 |
| Dimensional Fund Advisors | 374.0k | 0.46% | $91.5M | added +3.2% | 2018 Q4 |
| First Trust Advisors LP | 369.4k | 0.45% | $90.4M | trimmed -17.3% | 2018 Q4 |
| SEI Investments CO | 367.7k | 0.45% | $90.0M | added +125.3% | 2020 Q2 |
| Voya Investment Management LLC | 348.6k | 0.43% | $85.3M | trimmed -41.5% | 2019 Q2 |
| Raymond James Financial INC | 331.7k | 0.41% | $81.2M | added +11.2% | 2018 Q1 |
Largest 50 of 788 shown; the full ranked, searchable register is at boothcheck.com/holders/MDB. 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.