Who owns MDB (MDB)
Which tracked institutional funds hold MDB, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See MDB company fundamentals →
Ownership as of the 2026-Q1 13F filings. 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on MDB is one-sided between 2025-Q4 and 2026-Q1: 127 added or opened and 469 trimmed or exited — on balance reducing.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
MDB’s largest tracked holder by dollar value, VANGUARD GROUP INC, sizes it at 0.1% of its own reported 13F book, while the median holder sizes it at 0.1% of theirs — a 0.0pp gap the other way — the median holder sizes MDB more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in MDB divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 809 tracked filers holding MDB, 456 increased or opened the position and 470 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in MDB between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 60
- VANGUARD PORTFOLIO MANAGEMENT LLC$1.1B
- VANGUARD CAPITAL MANAGEMENT LLC$861M
- VANGUARD FIDUCIARY TRUST CO$123M
- WORLDQUANT MILLENNIUM ADVISORS LLC$42M
- RENAISSANCE TECHNOLOGIES LLC$34M
- VANGUARD ASSET MANAGEMENT, Ltd$34M
Full exits 97
- VANGUARD GROUP INC$3.6B
- MARSHALL WACE, LLP$201M
- Contour Asset Management LLC$83M
- LMR Partners LLP$57M
- Rokos Capital Management LLP$55M
- MANE GLOBAL CAPITAL MANAGEMENT LP$34M
Largest adds
- WELLINGTON MANAGEMENT GROUP LLP$128M
- Artisan Partners Limited Partnership$121M
- NEUBERGER BERMAN GROUP LLC$83M
- AQR CAPITAL MANAGEMENT LLC$77M
- Eurizon Capital SGR S.p.A.$48M
- OFI INVEST ASSET MANAGEMENT$42M
Largest trims
- BlackRock, Inc.$1.6B
- FMR LLC$464M
- NORGES BANK$444M
- ARROWSTREET CAPITAL, LIMITED PARTNERSHIP$396M
- D. E. Shaw & Co., Inc.$384M
- ValueAct Holdings, L.P.$336M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 4,501,522 | $1.1B | 5.9% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 3,518,839 | $861M | 4.6% | 2026-Q1 |
| BlackRock, Inc. trimmed | 3,399,780 | $832M | 4.4% | 2026-Q1 |
| FMR LLC trimmed | 2,187,066 | $535M | 2.9% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 2,092,486 | $512M | 2.7% | 2026-Q1 |
| DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main added | 1,953,175 | $478M | 2.5% | 2026-Q1 |
| STATE STREET CORP added | 1,844,118 | $451M | 2.4% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,527,842 | $373M | 2.0% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 1,311,775 | $318M | 1.7% | 2026-Q1 |
| Artisan Partners Limited Partnership added | 1,227,170 | $300M | 1.6% | 2026-Q1 |
| MORGAN STANLEY trimmed | 1,217,996 | $298M | 1.6% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC trimmed | 1,084,543 | $265M | 1.4% | 2026-Q1 |
| ValueAct Holdings, L.P. trimmed | 1,037,800 | $254M | 1.4% | 2026-Q1 |
| Capital World Investors added | 1,017,235 | $249M | 1.3% | 2026-Q1 |
| Jericho Capital Asset Management L.P. | 996,540 | $244M | 1.3% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 1,033,820 | $243M | 1.3% | 2026-Q1 |
| D. E. Shaw & Co., Inc. trimmed | 931,570 | $228M | 1.2% | 2026-Q1 |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ added | 891,744 | $220M | 1.2% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP added | 899,483 | $220M | 1.2% | 2026-Q1 |
| Invesco Ltd. trimmed | 854,701 | $209M | 1.1% | 2026-Q1 |
| PRIMECAP MANAGEMENT CO/CA/ trimmed | 842,729 | $206M | 1.1% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 672,221 | $165M | 0.9% | 2026-Q1 |
| T. Rowe Price Investment Management, Inc. added | 664,568 | $163M | 0.9% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 609,569 | $149M | 0.8% | 2026-Q1 |
| Employees Provident Fund Board added | 584,559 | $143M | 0.8% | 2026-Q1 |
| Swedbank AB trimmed | 580,686 | $142M | 0.8% | 2026-Q1 |
| CITADEL ADVISORS LLC trimmed | 557,057 | $136M | 0.7% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 555,305 | $136M | 0.7% | 2026-Q1 |
| Harel Insurance Investments & Financial Services Ltd. added | 549,970 | $135M | 0.7% | 2026-Q1 |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. trimmed | 544,700 | $133M | 0.7% | 2026-Q1 |
| Legal & General Group Plc added | 537,624 | $132M | 0.7% | 2026-Q1 |
| NORGES BANK trimmed | 746,762 | $131M | 0.7% | 2026-Q1 |
| SRS Investment Management, LLC added | 526,942 | $129M | 0.7% | 2026-Q1 |
| FEDERATED HERMES, INC. trimmed | 524,311 | $128M | 0.7% | 2026-Q1 |
| NORTHERN TRUST CORP added | 517,136 | $127M | 0.7% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 503,209 | $123M | 0.7% | 2026-Q1 |
| DEUTSCHE BANK AG\ trimmed | 480,278 | $118M | 0.6% | 2026-Q1 |
| NEUBERGER BERMAN GROUP LLC added | 474,483 | $116M | 0.6% | 2026-Q1 |
| Point72 Asset Management, L.P. trimmed | 474,357 | $116M | 0.6% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. trimmed | 273,335 | $115M | 0.6% | 2026-Q1 |
| Robeco Institutional Asset Management B.V. added | 468,505 | $115M | 0.6% | 2026-Q1 |
| UBS Group AG trimmed | 465,701 | $114M | 0.6% | 2026-Q1 |
| FIL Ltd trimmed | 464,411 | $114M | 0.6% | 2026-Q1 |
| FRED ALGER MANAGEMENT, LLC trimmed | 438,613 | $107M | 0.6% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 421,528 | $103M | 0.5% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 411,331 | $101M | 0.5% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 407,349 | $100M | 0.5% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 399,310 | $98M | 0.5% | 2026-Q1 |
| Pictet Asset Management Holding SA added | 390,253 | $96M | 0.5% | 2026-Q1 |
| 1832 Asset Management L.P. trimmed | 377,000 | $92M | 0.5% | 2026-Q1 |
| Amundi added | 376,447 | $92M | 0.5% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 373,992 | $92M | 0.5% | 2026-Q1 |
| FIRST TRUST ADVISORS LP trimmed | 369,448 | $90M | 0.5% | 2026-Q1 |
| SEI INVESTMENTS CO added | 367,663 | $90M | 0.5% | 2026-Q1 |
| VOYA INVESTMENT MANAGEMENT LLC trimmed | 348,572 | $85M | 0.5% | 2026-Q1 |
| Polar Capital Holdings Plc trimmed | 330,791 | $81M | 0.4% | 2026-Q1 |
| RAYMOND JAMES FINANCIAL INC added | 331,731 | $80M | 0.4% | 2026-Q1 |
| CANADA PENSION PLAN INVESTMENT BOARD added | 324,050 | $79M | 0.4% | 2026-Q1 |
| Nuveen, LLC added | 304,284 | $74M | 0.4% | 2026-Q1 |
| CONGRESS ASSET MANAGEMENT CO added | 301,897 | $74M | 0.4% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 287,162 | $70M | 0.4% | 2026-Q1 |
| Ensign Peak Advisors, Inc trimmed | 276,559 | $68M | 0.4% | 2026-Q1 |
| BLAIR WILLIAM & CO/IL trimmed | 270,982 | $66M | 0.4% | 2026-Q1 |
| Avala Global LP trimmed | 269,072 | $66M | 0.4% | 2026-Q1 |
| TREMBLANT CAPITAL GROUP added | 267,458 | $65M | 0.3% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC trimmed | 267,414 | $65M | 0.3% | 2026-Q1 |
| BAILLIE GIFFORD & CO | 267,331 | $65M | 0.3% | 2026-Q1 |
| ROYAL BANK OF CANADA trimmed | 261,902 | $64M | 0.3% | 2026-Q1 |
| Spyglass Capital Management LLC trimmed | 253,174 | $62M | 0.3% | 2026-Q1 |
| Allspring Global Investments Holdings, LLC added | 240,646 | $60M | 0.3% | 2026-Q1 |
| Swiss National Bank added | 238,840 | $58M | 0.3% | 2026-Q1 |
| Whale Rock Capital Management LLC trimmed | 224,648 | $55M | 0.3% | 2026-Q1 |
| Champlain Investment Partners, LLC trimmed | 223,064 | $55M | 0.3% | 2026-Q1 |
| FRONTIER CAPITAL MANAGEMENT CO LLC trimmed | 214,316 | $52M | 0.3% | 2026-Q1 |
| CI INVESTMENTS INC. added | 213,604 | $52M | 0.3% | 2026-Q1 |
| Candriam S.C.A. added | 213,067 | $52M | 0.3% | 2026-Q1 |
| Eurizon Capital SGR S.p.A. added | 212,893 | $52M | 0.3% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC trimmed | 206,799 | $51M | 0.3% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS added | 203,347 | $50M | 0.3% | 2026-Q1 |
| CITIGROUP INC trimmed | 200,537 | $49M | 0.3% | 2026-Q1 |
| Fiera Capital Corp added | 183,091 | $45M | 0.2% | 2026-Q1 |
| OFI INVEST ASSET MANAGEMENT added | 204,895 | $44M | 0.2% | 2026-Q1 |
| NORDEA INVESTMENT MANAGEMENT AB added | 177,624 | $43M | 0.2% | 2026-Q1 |
| Danica Pension, Livsforsikringsaktieselskab trimmed | 172,280 | $42M | 0.2% | 2026-Q1 |
| NOMURA ASSET MANAGEMENT CO LTD added | 171,683 | $42M | 0.2% | 2026-Q1 |
| Lead Edge Capital Management, LLC added | 170,425 | $42M | 0.2% | 2026-Q1 |
| WORLDQUANT MILLENNIUM ADVISORS LLC added | 170,124 | $42M | 0.2% | 2026-Q1 |
| KBC Group NV added | 168,018 | $41M | 0.2% | 2026-Q1 |
| Quantinno Capital Management LP added | 167,745 | $41M | 0.2% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 8,565,146 | $3.6B | 19.2% | 2025-Q4 stale |
| MARSHALL WACE, LLP added | 479,500 | $201M | 1.1% | 2025-Q4 stale |
| TIGER GLOBAL MANAGEMENT LLC added | 341,000 | $106M | 0.6% | 2025-Q3 stale |
| Contour Asset Management LLC trimmed | 198,944 | $83M | 0.4% | 2025-Q4 stale |
| Candlestick Capital Management LP new | 255,493 | $79M | 0.4% | 2025-Q3 stale |
| Connor, Clark & Lunn Investment Management Ltd. added | 232,167 | $72M | 0.4% | 2025-Q3 stale |
| Southpoint Capital Advisors LP new | 200,000 | $62M | 0.3% | 2025-Q3 stale |
| LMR Partners LLP trimmed | 137,000 | $57M | 0.3% | 2025-Q4 stale |
| Rokos Capital Management LLP added | 131,234 | $55M | 0.3% | 2025-Q4 stale |
| MAVERICK CAPITAL LTD trimmed | 136,932 | $43M | 0.2% | 2025-Q3 stale |
| Freestone Grove Partners LP added | 199,805 | $42M | 0.2% | 2025-Q2 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.