NAMS · NewAmsterdam Pharma Co N.V. · Holdings
Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.
Institutional Ownership Trend
Superinvestors Holding NAMS
All superinvestors →Holder Concentration
Across 200 13F filersWho Holds NAMS
Last 8 quarters through Sep 30, 2026 (filing window open)Each kind of 13F filer's share of the common shares 13F filers report. Holder type comes from regulatory records, never the filer's name; style, turnover and horizon are measured from each filer's own 13F book. The quarter selector does not change this card.
Jun 30, 2026, the newest closed quarter: 197 filers, like-for-like change -1.3%; actively managed books -1.0%; index-like books -1.0%.
| Holder type | Share | Filers | Change |
|---|---|---|---|
| Registered adviser | 49.2% | 90 | +0.5% |
| Exempt adviser | 1.9% | 5 | -20.5% |
| Adviser | 13.2% | 6 | +15.1% |
| Bank | 2.3% | 14 | -7.0% |
| Benefit plan | 0.1% | 3 | +43.7% |
| Non-US | 1.0% | 8 | -20.7% |
| Holding company | 12.1% | 8 | -17.3% |
| Broker-dealer | 0.0% | 0 | — |
| Insurer | 0.0% | 0 | — |
| Unknown | 20.2% | 63 | +0.7% |
| Style | Share | Filers | Change |
|---|---|---|---|
| Index-like | 4.3% | 19 | -1.0% |
| Systematic-like | 2.6% | 23 | +35.0% |
| Concentrated | 34.6% | 22 | -6.7% |
| Diversified active | 56.7% | 131 | +1.6% |
| Unknown | 1.8% | 2 | -17.4% |
| Not measured | 0.0% | 0 | — |
| Turnover | Share | Filers | Change |
|---|---|---|---|
| Low turnover | 53.2% | 81 | +6.0% |
| Medium turnover | 29.7% | 60 | -20.0% |
| High turnover | 14.4% | 41 | +23.8% |
| Unknown | 2.6% | 15 | +12.1% |
| Not measured | 0.0% | 0 | — |
| Holding horizon | Share | Filers | Change |
|---|---|---|---|
| Short horizon | 4.5% | 27 | +25.0% |
| Medium horizon | 12.6% | 33 | -4.7% |
| Long horizon | 65.3% | 114 | -0.8% |
| Unknown | 17.6% | 23 | -5.7% |
| Not measured | 0.0% | 0 | — |
| 13F book size | Share | Filers | Change |
|---|---|---|---|
| Under $1B | 10.5% | 35 | -8.5% |
| $1B to $10B | 30.2% | 50 | -6.6% |
| $10B to $100B | 23.0% | 53 | +5.9% |
| $100B or more | 36.2% | 59 | +1.4% |
| Not measured | 0.0% | 0 | — |
| Client base | Share | Filers | Change |
|---|---|---|---|
| Individuals and high net worth | 0.2% | 19 | -12.5% |
| Pooled investment vehicles | 41.1% | 38 | +1.3% |
| Registered funds and BDCs | 3.6% | 14 | +16.2% |
| Pension and profit sharing plans | 0.0% | 2 | +20900.0% |
| Insurance companies | 0.1% | 2 | +12.0% |
| Governments and sovereign funds | 0.5% | 3 | +15.2% |
| Other investment advisers | 0.0% | 1 | new |
| Diversified | 3.7% | 11 | -18.1% |
| Corporations | 0.0% | 0 | — |
| Unknown | 50.8% | 107 | -3.0% |
| Private funds | Share | Filers | Change |
|---|---|---|---|
| Hedge funds | 20.3% | 47 | -2.1% |
| Private equity funds | 0.6% | 5 | -39.8% |
| Venture capital funds | 9.8% | 3 | -8.7% |
| Real estate funds | 0.0% | 3 | -50.5% |
| Other private funds | 3.1% | 8 | +22.6% |
| Mixed private funds | 16.1% | 2 | +6.5% |
| Private funds, type not stated | 0.4% | 2 | +13.4% |
| No private funds | 0.9% | 25 | +18.0% |
| Securitized asset funds | 0.0% | 0 | -100.0% |
| Unknown | 48.9% | 102 | -2.2% |
| Location | Share | Filers | Change |
|---|---|---|---|
| United States | 84.8% | 145 | -1.0% |
| Outside the US | 15.1% | 51 | -3.1% |
| Unknown | 0.1% | 1 | +82.0% |
The Sep 30, 2026 filing window is still open, so its bar carries the Jun 30, 2026 positions of filers that have not filed yet.
How the mix is measured
Shares are 13F common shares restated to today's split basis; options and principal amounts are left out. The change compares only filers with a 13F in both quarters and keeps each filer in its bucket of the later quarter on both sides; a filer that continues under a new CIK is compared through its successor. Holder type comes from each filer's current regulatory profile; client base and private funds come from the Form ADV roster current at each quarter end (rosters from December 2019, so an earlier quarter reads Unknown). Style, turnover, horizon and book size are measured from each filer's 13F book in the newest measured quarter, and Not measured means none was. Actively managed books are those measured systematic-like, concentrated or diversified active.
Excluded 1 holder with no observed 2026-03-31 13F and 2 holders with no observed 2026-06-30 13F. Compared across CIK changes: JANUS HENDERSON GROUP PLC continues as Jupiter Topco LLC.
Conviction and Crowding
194 13F filers, quarter ended Jun 30, 2026Measured across every 13F filer's common-share book once the quarter's filing window closed. Crowding counts filers with high turnover or that advise private funds on Form ADV.
Managers in the top fifth by current three-year FundScore alpha were net sellers of $98,860 (0 buying, 1 selling).
Estimated Holder Cost Basis
Quarter ended Jun 30, 2026, on that quarter's share basisEstimated, never filed: each 13F buy is costed at its quarter's average traded price and each sale keeps the average cost, so this is what holders paid on average if they traded evenly through each quarter.
Estimated cost covers 92.3% of the 13F shares; positions already held when a filer's 13F history starts, or bought in a quarter without a trusted average price, have no estimate.
Shared Holders
Companies NAMS's active holders also own, quarter ended Jun 30, 2026| # | Company | Shared holders |
|---|---|---|
| 1 | ORKA Oruka Therapeutics, Inc. | 14 |
| 2 | INSM INSMED Inc | 17 |
| 3 | COAG Hemab Therapeutics Holdings, Inc. | 6 |
| 4 | SION Sionna Therapeutics, Inc. | 8 |
| 5 | ELVN Enliven Therapeutics, Inc. | 11 |
| 6 | IRON Disc Medicine, Inc. | 9 |
| 7 | EQ Equillium, Inc. | 5 |
| 8 | XENE Xenon Pharmaceuticals Inc. | 11 |
| 9 | DMRA Damora Therapeutics, Inc. | 7 |
| 10 | SRRK Scholar Rock Holding Corp | 9 |
Shareholder Targets
13F filers that own its peers but not NAMS, quarter ended Jun 30, 2026Found through its holder-overlap peers: ORKA, INSM, COAG, SION, ELVN, IRON, EQ, XENE, DMRA, SRRK, SYRE, DNTH, PTGX, MLYS, PHVS, ALKS, CRNX, PRAX, ERAS, PBLS. 884 filers in all.
| # | Filer | In peers | Largest peers |
|---|---|---|---|
| 1 | VANGUARD CAPITAL MANAGEMENT LLC Registered adviser, Index-like | $4,022,177,783 19 held | INSM, PRAX, ALKS |
| 2 | BAKER BROS. ADVISORS LP Registered adviser, Concentrated | $2,345,637,177 10 held | INSM, PRAX, ALKS |
| 3 | RTW INVESTMENTS, LP Registered adviser, Diversified active | $2,255,771,753 8 held | PTGX, INSM, SYRE |
| 4 | Driehaus Capital Management LLC Registered adviser, Diversified active | $1,428,761,216 11 held | PRAX, XENE, SYRE |
| 5 | PERCEPTIVE ADVISORS LLC Registered adviser, Diversified active | $1,385,102,158 6 held | PRAX, SYRE, ORKA |
| 6 | T. Rowe Price Investment Management, Inc. Adviser, Diversified active | $1,377,506,548 9 held | ERAS, DNTH, INSM |
| 7 | Siren, L.L.C. Unknown, Diversified active | $1,341,814,202 12 held | SRRK, ERAS, ELVN |
| 8 | Venrock Adviser, LLC Registered adviser, Concentrated | $1,240,205,413 7 held | ORKA, ERAS, SYRE |
| 9 | FARALLON CAPITAL MANAGEMENT LLC Registered adviser, Diversified active | $1,179,438,578 3 held | PTGX, CRNX, PBLS |
| 10 | Fairmount Funds Management LLC Registered adviser, Concentrated | $920,754,225 4 held | ORKA, DNTH, DMRA |
Fund Ownership of NAMS by Fund Type
Registered funds' Form N-PORT reports for the quarter ended Jun 30, 2026Index funds and index ETFs hold 0.15% of shares outstanding.
| Fund type | Of shares outstanding | Shares |
|---|---|---|
| Index funds | 0.00% | 452 |
| Index ETFs | 0.15% | 177,603 |
| Active ETFs | 0.02% | 19,307 |
| Active funds | 0.80% | 950,900 |
| Unclassified | 0.00% | 2,944 |
| All registered funds | 0.96% | 1,151,206 |
How fund types are measured
Each fund series counts once, with its latest Form N-PORT report dated inside the quarter; only long share positions count, restated to today's split basis. The fund type is the series' latest Form N-CEN answer on or before the quarter end (the index-fund box and the exchange-traded flag), never its name. Unclassified funds have no usable N-CEN; unit investment trusts are among them, so index ownership is a floor. Funds sit inside their advisers' 13F reports, so these shares overlap the 13F figures and are never added to them.
| Holder | Value (USD) | % of 13F | Shares | Type | Filed | Open |
|---|---|---|---|---|---|---|
| Mid Frazier Life Sciences Management, L.P. Registered adviser | $613,032,888 | 14.45% | 18,088,902 | Shares | 2026-08-14 | |
| Mega Capital World Investors Adviser | $414,493,576 | 9.77% | 12,230,557 | Shares | 2026-08-12 | |
| Mega FMR LLC Holding company | $350,411,177 | 8.26% | 10,339,663 | Shares | 2026-08-13 | |
| Large RA CAPITAL MANAGEMENT, L.P. Registered adviser | $323,655,972 | 7.63% | 9,550,191 | Shares | 2026-08-14 | |
| Small FCPM III SERVICES B.V. | $287,738,062 | 6.78% | 8,490,353 | Shares | 2026-08-14 | |
| Mid DEERFIELD MANAGEMENT COMPANY, L.P. Registered adviser | $144,533,699 | 3.41% | 4,264,789 | Shares | 2026-08-14 | |
| Large VIKING GLOBAL INVESTORS LP Registered adviser | $142,458,885 | 3.36% | 4,203,567 | Shares | 2026-08-14 | |
| Mid Bain Capital Life Sciences Investors, LLC | $129,004,521 | 3.04% | 3,806,566 | Shares | 2026-08-14 | |
| Large MAVERICK CAPITAL LTD Registered adviser | $110,745,809 | 2.61% | 3,267,802 | Shares | 2026-08-14 | |
| Mid Duquesne Family Office LLC | $104,047,247 | 2.45% | 3,070,146 | Shares | 2026-08-14 | |
| Mega Jupiter Topco LLC | $85,934,262 | 2.03% | 2,535,682 | Shares | 2026-08-14 | |
| Small Medicxi Ventures Management (Jersey) Ltd Exempt adviser | $74,850,775 | 1.76% | 2,208,639 | Shares | 2026-08-04 | |
| Mega JENNISON ASSOCIATES LLC Registered adviser | $71,246,471 | 1.68% | 2,102,286 | Shares | 2026-08-03 | |
| Large Orbis Allan Gray Ltd | $59,227,078 | 1.40% | 1,747,627 | Shares | 2026-08-14 | |
| Large Polar Capital Holdings Plc Registered adviser | $58,443,915 | 1.38% | 1,724,518 | Shares | 2026-08-14 | |
| Mega Capital International Investors Adviser | $58,409,245 | 1.38% | 1,723,495 | Shares | 2026-08-12 | |
| Mega GOLDMAN SACHS GROUP INC Holding company | $52,357,033 | 1.23% | 1,544,911 | Shares | 2026-08-14 | |
| Large WESTFIELD CAPITAL MANAGEMENT CO LP Registered adviser | $52,071,036 | 1.23% | 1,536,472 | Shares | 2026-08-12 | |
| Large Castle Hook Partners LP Registered adviser | $46,463,359 | 1.10% | 1,371,005 | Shares | 2026-08-14 | |
| Mega ALLIANCEBERNSTEIN L.P. Registered adviser | $42,699,366 | 1.01% | 1,259,940 | Shares | 2026-08-14 | |
| Mega AMERIPRISE FINANCIAL INC Adviser | $42,482,773 | 1.00% | 1,253,549 | Shares | 2026-08-14 | |
| Mega PRICE T ROWE ASSOCIATES INC /MD/ Registered adviser | $39,561,728 | 0.93% | 1,167,357 | Shares | 2026-08-14 | |
| Mega JPMORGAN CHASE & CO Bank | $38,395,842 | 0.91% | 1,132,955 | Shares | 2026-08-12 | |
| Large Aberdeen Group plc Holding company | $37,373,383 | 0.88% | 1,102,785 | Shares | 2026-07-31 | |
| Mega BlackRock, Inc. Holding company | $36,050,481 | 0.85% | 1,063,750 | Shares | 2026-08-07 | |
| Mega FRANKLIN RESOURCES INC Adviser | $33,683,847 | 0.79% | 993,917 | Shares | 2026-08-13 | |
| Mid TimesSquare Capital Management, LLC Registered adviser | $26,981,930 | 0.64% | 796,162 | Shares | 2026-08-07 | |
| Large BNP PARIBAS ASSET MANAGEMENT Holding S.A. Non-US | $26,472,832 | 0.62% | 781,140 | Shares | 2026-08-13 | |
| Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP | $25,564,142 | 0.60% | 754,327 | Shares | 2026-08-14 | |
| Large Woodline Partners LP Registered adviser | $25,501,852 | 0.60% | 752,489 | Shares | 2026-08-14 | |
| Mega BANK OF AMERICA CORP /DE/ Bank | $24,925,518 | 0.59% | 735,483 | Shares | 2026-08-14 | |
| Mid NWI MANAGEMENT LP Registered adviser | $23,790,780 | 0.56% | 702,000 | Shares | 2026-08-14 | |
| Mega AMERICAN CENTURY COMPANIES INC | $23,208,312 | 0.55% | 684,813 | Shares | 2026-08-12 | |
| Mega CITADEL ADVISORS LLC Registered adviser | $21,886,331 | 0.52% | 645,805 | Shares | 2026-09-02 | |
| Large Jefferies Financial Group Inc. Holding company | $20,334,000 | 0.48% | 600,000 | Put | 2026-08-17 | |
| Mid Rock Springs Capital Management LP Registered adviser | $19,749,194 | 0.47% | 582,744 | Shares | 2026-08-14 | |
| Small First Turn Management, LLC Registered adviser | $19,740,823 | 0.47% | 582,497 | Shares | 2026-08-14 | |
| Mega MORGAN STANLEY Holding company | $19,514,703 | 0.46% | 575,825 | Shares | 2026-08-13 | |
| Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP | $19,269,854 | 0.45% | 568,600 | Put | 2026-08-14 | |
| Large ADAGE CAPITAL PARTNERS GP, L.L.C. Registered adviser | $18,639,500 | 0.44% | 550,000 | Shares | 2026-08-14 | |
| Small Artia Global Partners LP Registered adviser | $17,078,391 | 0.40% | 503,936 | Shares | 2026-08-14 | |
| Mega MILLENNIUM MANAGEMENT LLC Registered adviser | $16,999,698 | 0.40% | 501,614 | Shares | 2026-08-14 | |
| Mid Cormorant Asset Management, LP Registered adviser | $16,945,000 | 0.40% | 500,000 | Shares | 2026-08-14 | |
| Mid PERCEPTIVE ADVISORS LLC Registered adviser | $16,945,000 | 0.40% | 500,000 | Put | 2026-08-14 | |
| Mega JANE STREET GROUP, LLC | $16,071,857 | 0.38% | 474,236 | Shares | 2026-08-14 | |
| Mid KENNEDY CAPITAL MANAGEMENT LLC Registered adviser | $14,280,364 | 0.34% | 421,374 | Shares | 2026-08-14 | |
| Mega Bank of New York Mellon Corp Bank | $11,973,266 | 0.28% | 353,298 | Shares | 2026-08-06 | |
| Large HRT FINANCIAL LP | $11,856,179 | 0.28% | 349,843 | Shares | 2026-08-14 | |
| Mega UBS Group AG Bank | $11,660,361 | 0.27% | 344,065 | Shares | 2026-08-13 | |
| Mid Slate Path Capital LP Registered adviser | $10,810,910 | 0.25% | 319,000 | Shares | 2026-08-14 | |
| Mid Frazier Life Sciences Management, L.P. Registered adviser NAMSW | $10,692,116 | 0.25% | 500,333 | Shares | 2026-08-14 | |
| Large LORD, ABBETT & CO. LLC Registered adviser | $10,389,318 | 0.24% | 306,560 | Shares | 2026-08-14 | |
| Large ExodusPoint Capital Management, LP Registered adviser | $10,313,879 | 0.24% | 304,334 | Shares | 2026-08-14 | |
| Mid Eversept Partners, LP Registered adviser | $9,335,712 | 0.22% | 275,471 | Shares | 2026-08-14 | |
| Mid Affinity Asset Advisors, LLC Registered adviser | $9,319,750 | 0.22% | 275,000 | Shares | 2026-08-13 | |
| Large SEB Asset Management AB | $9,240,244 | 0.22% | 272,654 | Shares | 2026-08-04 | |
| Small Atle Fund Management AB | $8,433,458 | 0.20% | 248,848 | Shares | 2026-07-24 | |
| Mid GILDER GAGNON HOWE & CO LLC Registered adviser | $7,593,732 | 0.18% | 224,070 | Shares | 2026-08-14 | |
| Mega WELLINGTON MANAGEMENT GROUP LLP Holding company | $7,413,403 | 0.17% | 218,749 | Shares | 2026-08-14 | |
| Large LMR Partners LLP Exempt adviser | $7,269,405 | 0.17% | 214,500 | Put | 2026-08-14 | |
| Large Ensign Peak Advisors, Inc | $7,199,015 | 0.17% | 212,423 | Shares | 2026-08-14 | |
| Mid ArrowMark Colorado Holdings LLC Registered adviser | $7,179,359 | 0.17% | 211,843 | Shares | 2026-08-13 | |
| Large RA CAPITAL MANAGEMENT, L.P. Registered adviser NAMSW | $7,123,326 | 0.17% | 333,333 | Shares | 2026-08-14 | |
| Mega DEUTSCHE BANK AG\ Non-US | $6,775,660 | 0.16% | 199,931 | Shares | 2026-08-07 | |
| Mega VANGUARD PORTFOLIO MANAGEMENT LLC Registered adviser | $6,156,931 | 0.15% | 181,674 | Shares | 2026-08-13 | |
| Small Decheng Capital LLC | $5,994,700 | 0.14% | 176,887 | Shares | 2026-08-14 | |
| Mega VICTORY CAPITAL MANAGEMENT INC Registered adviser | $5,851,549 | 0.14% | 172,663 | Shares | 2026-08-07 | |
| Mid PEREGRINE CAPITAL MANAGEMENT LLC Registered adviser | $5,743,948 | 0.14% | 169,488 | Shares | 2026-07-17 | |
| Large Point72 Asset Management, L.P. Registered adviser | $5,724,054 | 0.13% | 168,901 | Shares | 2026-08-14 | |
| Mid Affinity Asset Advisors, LLC Registered adviser NAMSW | $5,235,650 | 0.12% | 245,000 | Shares | 2026-08-13 | |
| Mid Mizuho Markets Cayman LP | $5,101,766 | 0.12% | 150,539 | Shares | 2026-07-24 | |
| Mega TD Asset Management Inc | $5,029,276 | 0.12% | 148,400 | Shares | 2026-08-04 | |
| Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP | $5,015,720 | 0.12% | 148,000 | Call | 2026-08-14 | |
| Mid XTX Topco Ltd | $4,914,321 | 0.12% | 145,008 | Shares | 2026-08-14 | |
| Mid Jump Financial, LLC | $4,897,511 | 0.12% | 144,512 | Shares | 2026-08-13 | |
| Small DCF Advisers, LLC | $4,778,490 | 0.11% | 141,000 | Shares | 2026-08-10 | |
| Mid KORNITZER CAPITAL MANAGEMENT INC /KS Registered adviser | $4,742,329 | 0.11% | 139,933 | Shares | 2026-07-31 | |
| Large Jefferies Financial Group Inc. Holding company | $4,159,251 | 0.10% | 122,728 | Shares | 2026-08-17 | |
| Large Handelsbanken Fonder AB Non-US | $4,148,136 | 0.10% | 122,400 | Shares | 2026-07-10 | |
| Mid BOOTHBAY FUND MANAGEMENT, LLC Registered adviser | $4,107,468 | 0.10% | 121,200 | Put | 2026-08-14 | |
| Mega Swiss National Bank | $4,104,079 | 0.10% | 121,100 | Shares | 2026-08-11 | |
| Mega D. E. Shaw & Co., Inc. | $4,085,812 | 0.10% | 120,561 | Shares | 2026-08-14 | |
| Mid ADAR1 Capital Management, LLC Registered adviser | $4,020,133 | 0.09% | 118,623 | Shares | 2026-08-14 | |
| Large ALPS ADVISORS INC Registered adviser | $4,003,934 | 0.09% | 118,145 | Shares | 2026-07-29 | |
| Mega STATE STREET CORP Bank | $3,904,636 | 0.09% | 115,215 | Shares | 2026-09-22 | |
| Large Walleye Capital LLC Registered adviser | $3,789,545 | 0.09% | 111,819 | Shares | 2026-08-03 | |
| Mega GEODE CAPITAL MANAGEMENT, LLC Registered adviser | $3,564,177 | 0.08% | 105,169 | Shares | 2026-08-12 | |
| Mega Swedbank AB | $3,527,949 | 0.08% | 104,100 | Shares | 2026-07-15 | |
| Mega MANUFACTURERS LIFE INSURANCE COMPANY, THE | $3,261,302 | 0.08% | 96,232 | Shares | 2026-09-09 | |
| Mega NORTHERN TRUST CORP Bank | $3,184,676 | 0.08% | 93,971 | Shares | 2026-08-13 | |
| Large Caption Management, LLC Registered adviser | $3,124,658 | 0.07% | 92,200 | Put | 2026-08-14 | |
| Large Squarepoint Ops LLC Registered adviser | $3,118,761 | 0.07% | 92,026 | Shares | 2026-08-14 | |
| Small Moody Aldrich Partners LLC Registered adviser | $3,071,010 | 0.07% | 90,617 | Shares | 2026-07-15 | |
| Large Schonfeld Strategic Advisors LLC Registered adviser | $3,042,135 | 0.07% | 89,765 | Shares | 2026-08-14 | |
| Mid Bellevue Group AG Non-US | $2,948,226 | 0.07% | 86,994 | Shares | 2026-08-14 | |
| Mid ALGERT GLOBAL LLC Registered adviser | $2,756,612 | 0.06% | 81,340 | Shares | 2026-08-13 | |
| Large Man Group plc | $2,739,396 | 0.06% | 80,832 | Shares | 2026-08-14 | |
| Large TUDOR INVESTMENT CORP ET AL Registered adviser | $2,692,899 | 0.06% | 79,460 | Shares | 2026-08-14 | |
| Small STEMPOINT CAPITAL LP Registered adviser | $2,629,491 | 0.06% | 77,589 | Shares | 2026-08-14 | |
| Small Headlands Technologies LLC | $2,451,433 | 0.06% | 72,335 | Shares | 2026-08-13 |
Showing the top 100 of 216 holders. Create a free account to see every holder, past quarters, search, filters and CSV export.