Who owns GMAB
Which tracked institutional funds hold GMAB, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See GMAB 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
41 tracked funds added or opened GMAB while 75 trimmed or exited it between 2025-Q4 and 2026-Q1 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
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
GMAB’s largest tracked holder by dollar value, Orbis Allan Gray Ltd, sizes it at 1.5% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 1.4pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in GMAB 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 271 tracked filers holding GMAB, 145 increased or opened the position and 161 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.
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 GMAB 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 17
- Deep Track Capital, LP$98M
- DEERFIELD MANAGEMENT COMPANY, L.P.$66M
- Sofinnova Investments, Inc.$20M
- MOORE CAPITAL MANAGEMENT, LP$6M
- Tidal Investments LLC$5M
- JANE STREET GROUP, LLC$3M
Full exits 26
- Brandywine Global Investment Management, LLC$32M
- SUSQUEHANNA INTERNATIONAL GROUP, LLP$19M
- Balyasny Asset Management L.P.$12M
- Woodline Partners LP$11M
- TWO SIGMA ADVISERS, LP$10M
- NEOS Investment Management LLC$4M
Largest adds
- TWO SIGMA INVESTMENTS, LP$35M
- FRANKLIN RESOURCES INC$31M
- FIRST TRUST ADVISORS LP$25M
- MILLENNIUM MANAGEMENT LLC$18M
- Qube Research & Technologies Ltd$17M
- FEDERATED HERMES, INC.$13M
Largest trims
- Orbis Allan Gray Ltd$97M
- ALLIANCEBERNSTEIN L.P.$41M
- ARROWSTREET CAPITAL, LIMITED PARTNERSHIP$20M
- BlackRock, Inc.$20M
- Harding Loevner LP$17M
- GOLDMAN SACHS GROUP INC$16M
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 |
|---|---|---|---|---|
| Orbis Allan Gray Ltd trimmed | 12,925,578 | $347M | 14.5% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. trimmed | 9,557,149 | $294M | 12.3% | 2026-Q1 |
| Paradigm Biocapital Advisors LP added | 7,967,836 | $214M | 8.9% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 4,975,324 | $133M | 5.6% | 2026-Q1 |
| BlackRock, Inc. trimmed | 4,536,565 | $122M | 5.1% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC added | 4,414,550 | $118M | 5.0% | 2026-Q1 |
| Deep Track Capital, LP added | 3,663,250 | $98M | 4.1% | 2026-Q1 |
| Harding Loevner LP trimmed | 3,231,601 | $87M | 3.6% | 2026-Q1 |
| DEERFIELD MANAGEMENT COMPANY, L.P. new | 2,462,000 | $66M | 2.8% | 2026-Q1 |
| FIRST TRUST ADVISORS LP added | 2,461,342 | $66M | 2.8% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 2,339,432 | $63M | 2.6% | 2026-Q1 |
| MORGAN STANLEY added | 2,184,701 | $59M | 2.5% | 2026-Q1 |
| FEDERATED HERMES, INC. added | 1,251,590 | $34M | 1.4% | 2026-Q1 |
| FRANKLIN RESOURCES INC added | 1,193,145 | $32M | 1.3% | 2026-Q1 |
| Pictet Asset Management Holding SA trimmed | 1,077,471 | $29M | 1.2% | 2026-Q1 |
| NORTHERN TRUST CORP trimmed | 950,534 | $26M | 1.1% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 931,259 | $25M | 1.0% | 2026-Q1 |
| ENVESTNET ASSET MANAGEMENT INC added | 862,301 | $23M | 1.0% | 2026-Q1 |
| FMR LLC trimmed | 809,160 | $22M | 0.9% | 2026-Q1 |
| Russell Investments Group, Ltd. added | 797,068 | $21M | 0.9% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 792,293 | $21M | 0.9% | 2026-Q1 |
| Perpetual Ltd trimmed | 758,503 | $20M | 0.9% | 2026-Q1 |
| Sofinnova Investments, Inc. new | 752,261 | $20M | 0.8% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 677,346 | $18M | 0.8% | 2026-Q1 |
| Alyeska Investment Group, L.P. added | 645,481 | $17M | 0.7% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC added | 538,944 | $14M | 0.6% | 2026-Q1 |
| CIBC WORLD MARKET INC. added | 488,266 | $13M | 0.5% | 2026-Q1 |
| OPPENHEIMER ASSET MANAGEMENT INC. added | 457,508 | $12M | 0.5% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN added | 319,592 | $9M | 0.4% | 2026-Q1 |
| Hudson Bay Capital Management LP trimmed | 310,000 | $8M | 0.3% | 2026-Q1 |
| UBS Group AG added | 298,132 | $8M | 0.3% | 2026-Q1 |
| Quantinno Capital Management LP added | 282,498 | $8M | 0.3% | 2026-Q1 |
| EAGLE GLOBAL ADVISORS LLC trimmed | 244,565 | $7M | 0.3% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ trimmed | 241,520 | $6M | 0.3% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS added | 227,587 | $6M | 0.3% | 2026-Q1 |
| ASSETMARK, INC trimmed | 224,144 | $6M | 0.3% | 2026-Q1 |
| JPMORGAN CHASE & CO trimmed | 222,607 | $6M | 0.2% | 2026-Q1 |
| MOORE CAPITAL MANAGEMENT, LP new | 211,705 | $6M | 0.2% | 2026-Q1 |
| SUPERSTRING CAPITAL MANAGEMENT LP added | 196,709 | $5M | 0.2% | 2026-Q1 |
| LPL Financial LLC trimmed | 188,637 | $5M | 0.2% | 2026-Q1 |
| Tidal Investments LLC new | 184,124 | $5M | 0.2% | 2026-Q1 |
| AIMZ Investment Advisors, LLC trimmed | 160,910 | $4M | 0.2% | 2026-Q1 |
| FOLKETRYGDFONDET trimmed | 160,773 | $4M | 0.2% | 2026-Q1 |
| ROYAL BANK OF CANADA added | 150,135 | $4M | 0.2% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 127,571 | $3M | 0.1% | 2026-Q1 |
| Creative Planning trimmed | 118,596 | $3M | 0.1% | 2026-Q1 |
| JANE STREET GROUP, LLC trimmed | 98,432 | $3M | 0.1% | 2026-Q1 |
| US BANCORP \DE\ trimmed | 95,548 | $3M | 0.1% | 2026-Q1 |
| SEI INVESTMENTS CO added | 93,012 | $2M | 0.1% | 2026-Q1 |
| SummitTX Capital, L.P. new | 84,354 | $2M | 0.1% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC trimmed | 82,017 | $2M | 0.1% | 2026-Q1 |
| Ishara Investments LP added | 82,000 | $2M | 0.1% | 2026-Q1 |
| Cetera Investment Advisers trimmed | 81,420 | $2M | 0.1% | 2026-Q1 |
| STIFEL FINANCIAL CORP added | 79,105 | $2M | 0.1% | 2026-Q1 |
| INGALLS & SNYDER LLC trimmed | 72,891 | $2M | 0.1% | 2026-Q1 |
| Madison Asset Management, LLC added | 70,970 | $2M | 0.1% | 2026-Q1 |
| NATIXIS ADVISORS, LLC trimmed | 70,980 | $2M | 0.1% | 2026-Q1 |
| RAYMOND JAMES FINANCIAL INC added | 66,902 | $2M | 0.1% | 2026-Q1 |
| QRG CAPITAL MANAGEMENT, INC. added | 65,822 | $2M | 0.1% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 65,130 | $2M | 0.1% | 2026-Q1 |
| Dorsey Wright & Associates added | 64,388 | $2M | 0.1% | 2026-Q1 |
| AMERIPRISE FINANCIAL INC added | 61,924 | $2M | 0.1% | 2026-Q1 |
| Vestmark Advisory Solutions, Inc. trimmed | 59,306 | $2M | 0.1% | 2026-Q1 |
| Bank of New York Mellon Corp added | 58,921 | $2M | 0.1% | 2026-Q1 |
| Vanguard Personalized Indexing Management, LLC trimmed | 57,292 | $2M | 0.1% | 2026-Q1 |
| LEVEL FOUR ADVISORY SERVICES, LLC trimmed | 57,023 | $2M | 0.1% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 56,438 | $2M | 0.1% | 2026-Q1 |
| Mariner, LLC added | 56,309 | $2M | 0.1% | 2026-Q1 |
| CAPITAL FUND MANAGEMENT S.A. trimmed | 55,399 | $1M | 0.1% | 2026-Q1 |
| Callan Family Office, LLC trimmed | 55,047 | $1M | 0.1% | 2026-Q1 |
| NEUBERGER BERMAN GROUP LLC trimmed | 53,962 | $1M | 0.1% | 2026-Q1 |
| BANK OF MONTREAL /CAN/ trimmed | 52,688 | $1M | 0.1% | 2026-Q1 |
| Advisors Preferred, LLC added | 50,720 | $1M | 0.1% | 2026-Q1 |
| Ikarian Capital, LLC new | 175,000 | $53M | 2.2% | 2025-Q3 stale |
| Brandywine Global Investment Management, LLC trimmed | 1,031,464 | $32M | 1.3% | 2025-Q4 stale |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 612,323 | $19M | 0.8% | 2025-Q4 stale |
| DDD Partners, LLC added | 601,050 | $12M | 0.5% | 2025-Q1 stale |
| Balyasny Asset Management L.P. added | 379,364 | $12M | 0.5% | 2025-Q4 stale |
| Woodline Partners LP trimmed | 369,188 | $11M | 0.5% | 2025-Q4 stale |
| Point72 Asset Management, L.P. trimmed | 538,500 | $11M | 0.5% | 2025-Q2 stale |
| TWO SIGMA ADVISERS, LP trimmed | 340,000 | $10M | 0.4% | 2025-Q4 stale |
| TANG CAPITAL MANAGEMENT LLC | 200,000 | $6M | 0.3% | 2025-Q3 stale |
| Hardman Johnston Global Advisors LLC added | 226,911 | $4M | 0.2% | 2025-Q1 stale |
| NEOS Investment Management LLC added | 140,733 | $4M | 0.2% | 2025-Q4 stale |
| Private Wealth Advisors, LLC trimmed | 131,653 | $4M | 0.2% | 2025-Q4 stale |
| TEMA ETFS LLC added | 132,043 | $4M | 0.2% | 2025-Q3 stale |
| FRED ALGER MANAGEMENT, LLC added | 130,470 | $4M | 0.2% | 2025-Q4 stale |
| Optiver Holding B.V. trimmed | 125,914 | $4M | 0.2% | 2025-Q4 stale |
| Caption Management, LLC new | 186,082 | $4M | 0.2% | 2025-Q1 stale |
| Point72 Europe (London) LLP trimmed | 107,864 | $3M | 0.1% | 2025-Q3 stale |
| ABC ARBITRAGE SA trimmed | 105,871 | $3M | 0.1% | 2025-Q4 stale |
| SUMMIT SECURITIES GROUP LLC added | 152,832 | $3M | 0.1% | 2025-Q2 stale |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC trimmed | 84,302 | $3M | 0.1% | 2025-Q4 stale |
| OLD MISSION CAPITAL LLC trimmed | 78,905 | $2M | 0.1% | 2025-Q4 stale |
| GTS SECURITIES LLC added | 114,743 | $2M | 0.1% | 2025-Q2 stale |
| Campbell & CO Investment Adviser LLC added | 107,217 | $2M | 0.1% | 2025-Q2 stale |
| Mitsubishi UFJ Trust & Banking Corp added | 61,452 | $2M | 0.1% | 2025-Q4 stale |
| HRT FINANCIAL LP trimmed | 49,232 | $2M | 0.1% | 2025-Q4 stale |
| AVANTAX ADVISORY SERVICES, INC. trimmed | 71,635 | $1M | 0.1% | 2025-Q2 stale |
| Foresight Group Ltd Liability Partnership trimmed | 47,194 | $1M | 0.1% | 2025-Q3 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.