NewAmsterdam Pharma (NAMS)
NewAmsterdam Pharma on one page: short interest, daily short volume, fails to deliver, planned sales, large holders, 13F holders, earnings dates and insider trades. Listed on Nasdaq, classified by the SEC as pharmaceutical preparations.
14.1M
Short interest
settlement 2026-10-15
10.6
Days to cover
+1.3 days vs prior
46.8%
Short share of volume
2026-11-02
442
Fails to deliver
settlement 2026-10-07
Wed 4 Nov
Next earnings
estimated date
-$4.4M
Insider flow, 90 days
1 buys, 3 sells
As of 2026-11-02.
Short interest
FINRA, twice a month. The newest 48 settlements in the table, 48 in the chart. JSONAs of 15 October 2026, short interest in NAMS is 14,110,048 shares, down 1,550,396 shares over the last month. Over the last 48 readings it ranged from 718,042 shares (31 October 2024) to 19,045,378 shares (30 September 2026). At the reported average volume of 1.3M shares a day that is 10.6 days to cover.
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| Settlement | Shares short | Change | Avg daily volume | Days to cover |
|---|---|---|---|---|
| 2026-10-15 | 14,110,048 | -25.9% | 1,325,822 | 10.64 |
| 2026-09-30 | 19,045,378 | +21.6% | 2,028,041 | 9.39 |
| 2026-09-15 | 15,660,444 | +16.9% | 1,584,794 | 9.88 |
| 2026-08-31 | 13,392,021 | +5.8% | 1,002,245 | 13.36 |
| 2026-08-14 | 12,654,106 | +27.1% | 1,275,058 | 9.92 |
| 2026-07-31 | 9,959,761 | +8.5% | 1,019,147 | 9.77 |
| 2026-07-15 | 9,176,420 | +0.9% | 819,057 | 11.20 |
| 2026-06-30 | 9,091,198 | -0.9% | 1,310,033 | 6.94 |
| 2026-06-15 | 9,171,265 | +13.2% | 1,257,012 | 7.30 |
| 2026-05-29 | 8,099,601 | +13.4% | 1,316,761 | 6.15 |
| 2026-05-15 | 7,139,696 | -9.4% | 1,921,567 | 3.72 |
| 2026-04-30 | 7,882,443 | +2.6% | 881,865 | 8.94 |
| 2026-04-15 | 7,682,586 | -4.5% | 879,465 | 8.74 |
| 2026-03-31 | 8,047,048 | +6.6% | 835,274 | 9.63 |
| 2026-03-13 | 7,545,738 | -1.5% | 1,028,858 | 7.33 |
| 2026-02-27 | 7,658,931 | +10.2% | 679,884 | 11.27 |
| 2026-02-13 | 6,951,469 | -2.1% | 651,314 | 10.67 |
| 2026-01-30 | 7,100,900 | +12.4% | 509,047 | 13.95 |
| 2026-01-15 | 6,319,202 | +1.7% | 864,424 | 7.31 |
| 2025-12-31 | 6,213,363 | -0.7% | 744,307 | 8.35 |
| 2025-12-15 | 6,258,439 | -6.3% | 1,205,967 | 5.19 |
| 2025-11-28 | 6,677,161 | -2.0% | 932,629 | 7.16 |
| 2025-11-14 | 6,817,112 | +6.1% | 1,095,048 | 6.23 |
| 2025-10-31 | 6,424,987 | -6.3% | 1,055,910 | 6.08 |
| 2025-10-15 | 6,855,986 | -10.3% | 1,493,276 | 4.59 |
| 2025-09-30 | 7,640,225 | -9.4% | 758,967 | 10.07 |
| 2025-09-15 | 8,434,726 | +12.5% | 1,257,745 | 6.71 |
| 2025-08-29 | 7,497,579 | +2.3% | 763,058 | 9.83 |
| 2025-08-15 | 7,328,645 | +2.1% | 843,591 | 8.69 |
| 2025-07-31 | 7,179,587 | +4.4% | 783,907 | 9.16 |
| 2025-07-15 | 6,878,437 | +0.0% | 843,800 | 8.15 |
| 2025-06-30 | 6,875,637 | -1.4% | 1,081,973 | 6.35 |
| 2025-06-13 | 6,970,274 | +6.3% | 1,015,361 | 6.86 |
| 2025-05-30 | 6,558,666 | -2.1% | 525,204 | 12.49 |
| 2025-05-15 | 6,698,285 | +23.5% | 827,356 | 8.10 |
| 2025-04-30 | 5,422,008 | +7.0% | 409,381 | 13.24 |
| 2025-04-15 | 5,069,436 | -5.1% | 1,372,707 | 3.69 |
| 2025-03-31 | 5,341,471 | +23.0% | 1,077,203 | 4.96 |
| 2025-03-14 | 4,342,156 | +42.8% | 1,466,343 | 2.96 |
| 2025-02-28 | 3,040,999 | +4.4% | 820,159 | 3.71 |
| 2025-02-14 | 2,911,595 | +4.0% | 502,960 | 5.79 |
| 2025-01-31 | 2,798,784 | -6.4% | 786,484 | 3.56 |
| 2025-01-15 | 2,991,295 | +0.8% | 552,894 | 5.41 |
| 2024-12-31 | 2,967,626 | +14.8% | 687,517 | 4.32 |
| 2024-12-13 | 2,584,311 | -0.2% | 1,893,055 | 1.37 |
| 2024-11-29 | 2,588,991 | +156.8% | 949,878 | 2.73 |
| 2024-11-15 | 1,008,065 | +40.4% | 586,187 | 1.72 |
| 2024-10-31 | 718,042 | +30.9% | 195,785 | 3.67 |
Daily short volume
FINRA Reg SHO, the last 30 sessions. JSONAs of 2 November 2026, the short share of NAMS volume is 46.8%, up 20.0 points over the last five sessions. Over the last 30 readings it ranged from 24.3% (27 October 2026) to 80.7% (9 October 2026). The latest reading is in line with the 30-session average of 48.2%, on 973K shares reported.
| Date | Short volume | Total volume | Short share | Exempt |
|---|---|---|---|---|
| 2026-11-02 | 455K | 973K | 46.8% | 215 |
| 2026-10-30 | 216K | 501K | 43.2% | 4,552 |
| 2026-10-29 | 138K | 479K | 28.7% | 100 |
| 2026-10-28 | 257K | 758K | 33.9% | 0 |
| 2026-10-27 | 313K | 1.3M | 24.3% | 0 |
| 2026-10-26 | 149K | 555K | 26.8% | 4,052 |
| 2026-10-23 | 358K | 1.0M | 35.0% | 5,124 |
| 2026-10-22 | 283K | 654K | 43.3% | 5,742 |
| 2026-10-21 | 319K | 660K | 48.3% | 0 |
| 2026-10-20 | 264K | 436K | 60.6% | 0 |
| 2026-10-19 | 104K | 236K | 43.9% | 0 |
| 2026-10-16 | 231K | 487K | 47.5% | 273 |
| 2026-10-15 | 98K | 248K | 39.6% | 0 |
| 2026-10-14 | 262K | 962K | 27.2% | 0 |
| 2026-10-13 | 165K | 339K | 48.5% | 200 |
| 2026-10-12 | 210K | 313K | 67.0% | 0 |
| 2026-10-09 | 472K | 585K | 80.7% | 0 |
| 2026-10-08 | 395K | 797K | 49.5% | 0 |
| 2026-10-07 | 271K | 463K | 58.7% | 0 |
| 2026-10-06 | 334K | 448K | 74.5% | 600 |
| 2026-10-05 | 297K | 423K | 70.0% | 1 |
| 2026-10-02 | 482K | 672K | 71.8% | 0 |
| 2026-10-01 | 390K | 706K | 55.2% | 0 |
| 2026-09-30 | 473K | 937K | 50.5% | 40,288 |
| 2026-09-29 | 246K | 462K | 53.3% | 100 |
| 2026-09-28 | 384K | 961K | 39.9% | 140 |
| 2026-09-25 | 272K | 571K | 47.6% | 0 |
| 2026-09-24 | 253K | 585K | 43.2% | 0 |
| 2026-09-23 | 456K | 758K | 60.2% | 0 |
| 2026-09-22 | 414K | 1.5M | 27.3% | 9,189 |
Fails to deliver
SEC, the last 30 settlement dates with a fail. JSONAs of 7 October 2026, the fails-to-deliver balance in NAMS is 442 shares, down 36,252 shares over the last settlement date. Over the last 30 readings it ranged from 2 shares (17 July 2026) to 115,916 shares (24 September 2026). The latest reading sits at the bottom of that range.
| Settlement | Shares failed | Price | Value |
|---|---|---|---|
| 2026-10-07 | 442 | $22.27 | $10K |
| 2026-10-02 | 36,694 | $24.16 | $887K |
| 2026-10-01 | 1,953 | $24.32 | $47K |
| 2026-09-24 | 115,916 | $22.68 | $2.6M |
| 2026-09-22 | 1,866 | $22.58 | $42K |
| 2026-09-18 | 2,763 | $21.93 | $61K |
| 2026-09-17 | 32 | $21.18 | $678 |
| 2026-09-09 | 10,021 | $25.63 | $257K |
| 2026-09-04 | 2,393 | $25.85 | $62K |
| 2026-09-03 | 4,953 | $25.59 | $127K |
| 2026-09-02 | 35 | $24.92 | $872 |
| 2026-08-31 | 50 | $25.90 | $1K |
| 2026-08-26 | 17,471 | $27.34 | $478K |
| 2026-08-25 | 7,987 | $26.85 | $214K |
| 2026-08-11 | 52 | $27.98 | $1K |
| 2026-08-06 | 2,826 | $27.42 | $77K |
| 2026-08-05 | 8 | $27.55 | $220 |
| 2026-08-04 | 2,180 | $27.49 | $60K |
| 2026-08-03 | 2,038 | $27.79 | $57K |
| 2026-07-29 | 138 | $27.98 | $4K |
| 2026-07-24 | 500 | $30.55 | $15K |
| 2026-07-23 | 500 | $31.70 | $16K |
| 2026-07-22 | 500 | $32.34 | $16K |
| 2026-07-21 | 3,976 | $29.67 | $118K |
| 2026-07-17 | 2 | $31.05 | $62 |
| 2026-07-08 | 1,911 | $36.99 | $71K |
| 2026-06-30 | 6,500 | $33.87 | $220K |
| 2026-06-29 | 54,787 | $33.24 | $1.8M |
| 2026-06-26 | 95,964 | $31.73 | $3.0M |
| 2026-06-15 | 2,997 | $30.40 | $91K |
Insider trades
SEC Form 4, newest first. JSONOver the last 90 days NAMS insiders reported 1 open-market buy ($227K) against 3 sells ($4.7M), so the dollar flow leans toward selling. Latest filing: Kastelein Johannes Jacob Pieter (Chief Scientific Officer) on 2026-09-30.
| Date | Insider | Title | Type | Shares | Price | Value | Owned after |
|---|---|---|---|---|---|---|---|
| 2026-09-30 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 50K | $25.03 | $1.3M | 69K |
| 2026-09-30 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Exercise or conversion | 50K | price not stated in the filing | not stated | 120K |
| 2026-09-14 | Davidson Michael H. | Chief Executive Officer | Buy | 10K | $22.65 | $227K | 793K |
| 2026-09-04 | Smither John W | Director | Sell | 2K | $25.32 | $41K | 9K |
| 2026-09-01 | Gunning Robert William | Vice President, Controller | Grant | 3K | $0.00 | $0 | 3K |
| 2026-08-24 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 125K | $26.91 | $3.4M | 69K |
| 2026-08-24 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Exercise or conversion | 125K | price not stated in the filing | not stated | 194K |
| 2026-07-20 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 3K | $31.71 | $92K | 24K |
| 2026-07-20 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 32K | $31.05 | $990K | 27K |
| 2026-07-20 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 70K | $29.96 | $2.1M | 59K |
| 2026-07-20 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 80K | $11.17 | $894K | 129K |
| 2026-07-20 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 25K | $11.90 | $298K | 49K |
| 2026-06-22 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 40K | $30.20 | $1.2M | 25K |
| 2026-06-22 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 25K | $10.90 | $273K | 49K |
| 2026-06-22 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 15K | $11.90 | $179K | 64K |
| 2026-06-22 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 300 | $30.73 | $9K | 24K |
| 2026-05-26 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 65K | $35.69 | $2.3M | 24K |
| 2026-05-26 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 5K | $10.90 | $55K | 89K |
| 2026-05-26 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 60K | $10.00 | $600K | 84K |
| 2026-03-11 | LANGE LOUIS G | Director | Sell | 446 | $31.23 | $14K | 10K |
| 2026-03-11 | LANGE LOUIS G | Director | Sell | 44K | $30.41 | $1.3M | 11K |
| 2026-03-09 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Exercise or conversion | 101K | price not stated in the filing | not stated | 171K |
| 2026-03-09 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 101K | $30.29 | $3.1M | 69K |
| 2026-03-09 | LANGE LOUIS G | Director | Exercise (in or at the money) | 45K | $11.50 | $513K | 55K |
| 2026-03-06 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 94K | $30.32 | $2.9M | 69K |
| 2026-03-06 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Exercise or conversion | 94K | price not stated in the filing | not stated | 163K |
| 2026-03-06 | LANGE LOUIS G | Director | Sell | 28K | $29.41 | $829K | 0 |
| 2026-03-05 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 104K | $30.30 | $3.2M | 69K |
| 2026-03-05 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Exercise or conversion | 104K | price not stated in the filing | not stated | 174K |
| 2026-03-02 | Davidson Michael H. | Chief Executive Officer | Exercise or conversion | 444K | price not stated in the filing | not stated | 618K |
| 2026-03-02 | Davidson Michael H. | Chief Executive Officer | Sell | 444K | $33.25 | $14.8M | 174K |
| 2026-02-26 | Davidson Michael H. | Chief Executive Officer | Sell | 18K | $34.44 | $617K | 174K |
| 2026-02-26 | Davidson Michael H. | Chief Executive Officer | Sell | 165K | $33.63 | $5.6M | 478K |
| 2026-02-26 | Davidson Michael H. | Chief Executive Officer | Exercise or conversion | 183K | price not stated in the filing | not stated | 643K |
| 2026-02-25 | Davidson Michael H. | Chief Executive Officer | Sell | 1K | $36.68 | $48K | 460K |
| 2026-02-25 | Davidson Michael H. | Chief Executive Officer | Sell | 10K | $35.96 | $375K | 461K |
| 2026-02-25 | Davidson Michael H. | Chief Executive Officer | Sell | 47K | $35.11 | $1.6M | 472K |
| 2026-02-25 | Davidson Michael H. | Chief Executive Officer | Exercise or conversion | 58K | price not stated in the filing | not stated | 518K |
| 2026-02-24 | Davidson Michael H. | Chief Executive Officer | Sell | 3K | $36.46 | $115K | 460K |
| 2026-02-24 | Davidson Michael H. | Chief Executive Officer | Sell | 62K | $36.13 | $2.2M | 463K |
| 2026-02-24 | Davidson Michael H. | Chief Executive Officer | Exercise or conversion | 65K | price not stated in the filing | not stated | 525K |
| 2026-02-20 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 31K | $35.46 | $1.1M | 54K |
| 2026-02-20 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 15K | $35.00 | $514K | 84K |
| 2026-01-28 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 33K | $31.80 | $1.0M | 24K |
| 2026-01-28 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 33K | $10.90 | $355K | 57K |
| 2026-01-27 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 40K | $32.62 | $1.3M | 24K |
| 2026-01-27 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 40K | $10.90 | $434K | 64K |
| 2026-01-26 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 309 | $33.45 | $10K | 24K |
| 2026-01-26 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 34K | $32.77 | $1.1M | 25K |
| 2026-01-26 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 34K | $10.90 | $375K | 59K |
| 2026-01-23 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 13K | $34.37 | $439K | 24K |
| 2026-01-23 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 25K | $33.44 | $850K | 37K |
| 2026-01-23 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 38K | $10.90 | $416K | 63K |
| 2026-01-21 | Somaiya Mayur Ian | Chief Financial Officer | Sell | 24K | $33.80 | $823K | 58K |
| 2026-01-21 | Somaiya Mayur Ian | Chief Financial Officer | Sell | 15K | $33.25 | $513K | 83K |
| 2026-01-21 | Somaiya Mayur Ian | Chief Financial Officer | Exercise or conversion | 40K | $9.26 | $368K | 98K |
| 2026-01-20 | Somaiya Mayur Ian | Chief Financial Officer | Sell | 20K | $32.38 | $635K | 58K |
| 2026-01-20 | Somaiya Mayur Ian | Chief Financial Officer | Sell | 40K | $31.78 | $1.3M | 78K |
| 2026-01-20 | Somaiya Mayur Ian | Chief Financial Officer | Sell | 900 | $30.64 | $28K | 118K |
| 2026-01-20 | Somaiya Mayur Ian | Chief Financial Officer | Exercise or conversion | 60K | $9.26 | $558K | 119K |
| 2026-01-07 | Somaiya Mayur Ian | Chief Financial Officer | Grant | 26K | price not stated in the filing | not stated | 58K |
| 2026-01-07 | Kooij Louise Frederika | Chief Accounting Officer | Grant | 12K | price not stated in the filing | not stated | 24K |
| 2026-01-07 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Grant | 26K | price not stated in the filing | not stated | 99K |
| 2026-01-07 | LANGE LOUIS G | Director | Grant | 3K | price not stated in the filing | not stated | 10K |
| 2026-01-07 | McKenna Mark C. | Director | Grant | 3K | price not stated in the filing | not stated | 10K |
| 2026-01-07 | Smither John W | Director | Grant | 3K | price not stated in the filing | not stated | 10K |
| 2026-01-07 | Lewis William | Director | Grant | 3K | price not stated in the filing | not stated | 10K |
| 2026-01-07 | Davidson Michael H. | Chief Executive Officer | Sell | 12K | ≈ $35.42, midpoint of the stated range $35.24 to $35.59 | ≈ $410K | 379K |
| 2026-01-07 | Davidson Michael H. | Chief Executive Officer | Grant | 81K | price not stated in the filing | not stated | 460K |
| 2026-01-07 | Gulfo Adele M. | Director | Grant | 3K | price not stated in the filing | not stated | 14K |
| 2026-01-07 | van der Kamp Hilde Johanna | Director | Grant | 3K | price not stated in the filing | not stated | 10K |
| 2026-01-05 | Somaiya Mayur Ian | Chief Financial Officer | Sell | 5K | $33.25 | $170K | 33K |
| 2026-01-05 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 3K | $33.25 | $88K | 12K |
| 2026-01-05 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 6K | $33.25 | $200K | 73K |
| 2025-12-26 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 44K | $35.30 | $1.5M | 15K |
| 2025-12-26 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 5K | $10.90 | $55K | 59K |
| 2025-12-26 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 39K | $10.00 | $389K | 54K |
| 2025-12-24 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 26K | $35.68 | $928K | 15K |
| 2025-12-24 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 26K | $10.00 | $260K | 41K |
| 2025-12-23 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 75K | $36.21 | $2.7M | 15K |
| 2025-12-23 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 75K | $10.00 | $751K | 90K |
| 2025-09-15 | Topper James N | Director | Buy | 660 | $23.70 | $16K | 3.0M |
| 2025-09-09 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 97K | $26.11 | $2.5M | 15K |
| 2025-09-09 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 53K | $25.31 | $1.3M | 112K |
| 2025-09-09 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 150K | $10.00 | $1.5M | 165K |
| 2025-09-08 | Topper James N | Director | Buy | 1K | $24.99 | $31K | 3.0M |
| 2025-09-03 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 18K | $25.09 | $453K | 15K |
| 2025-09-02 | Kooij Louise Frederika | Chief Accounting Officer | Exercise or conversion | 18K | price not stated in the filing | not stated | 33K |
| 2025-08-25 | Kooij Louise Frederika | Chief Accounting Officer | Sell | 8K | $24.86 | $206K | 15K |
| 2025-08-22 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 8K | $25.49 | $195K | 69K |
| 2025-08-22 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 42K | $25.08 | $1.1M | 77K |
| 2025-08-21 | Kastelein Johannes Jacob Pieter | Chief Scientific Officer | Sell | 50K | $24.29 | $1.2M | 119K |
| 2025-08-11 | Topper James N | Director | Buy | 471 | $23.98 | $11K | 3.0M |
| 2025-07-16 | Kling Douglas F | Chief Operating Officer | Sell | 51K | $21.10 | $1.1M | 44K |
| 2025-07-16 | Kling Douglas F | Chief Operating Officer | Exercise or conversion | 51K | $10.90 | $556K | 95K |
| 2025-07-15 | Kling Douglas F | Chief Operating Officer | Sell | 4K | $22.12 | $78K | 44K |
| 2025-07-15 | Kling Douglas F | Chief Operating Officer | Sell | 44K | $21.38 | $941K | 48K |
| 2025-07-15 | Kling Douglas F | Chief Operating Officer | Exercise or conversion | 48K | $10.90 | $519K | 92K |
| 2025-06-25 | Topper James N | Director | Buy | 1K | $18.26 | $23K | 3.0M |
| 2025-06-24 | Topper James N | Director | Buy | 3K | $18.43 | $46K | 3.0M |
Form 4 filings are due within two business days of the trade. Insiders sell for many reasons that say nothing about the company; open-market buys are rarer.
Planned sales (Form 144)
Newest first. JSON16 Form 144 notices on file for NAMS worth $267.9M at the prices reported; 0 in the last 90 days worth $0. Latest: Louis G. Lange filed on 2026-03-11 to sell 44,619 shares ($1.4M) from 2026-03-11.
| Filed | Seller | Shares | Market value | Of outstanding | Sale from | Broker |
|---|---|---|---|---|---|---|
| 2026-03-11 | Louis G. LangeAffiliate | 45K | $1.4M | 0.039% | 2026-03-11 | J.P. Morgan Securities LLC |
| 2026-03-06 | Louis G. LangeAffiliate | 28K | $879K | 0.025% | 2026-03-06 | J.P. Morgan Securities LLC |
| 2026-03-05 | Kastelein Johannes Jacob PieterAffiliate | 300K | $9.4M | 0.261% | 2026-03-02 | J.P. Morgan Securities LLC |
| 2026-03-02 | Michael H. DavidsonAffiliate | 444K | $15.7M | 0.386% | 2026-03-02 | J.P. Morgan Securities LLC |
| 2026-02-24 | Michael H. DavidsonAffiliate | 750K | $27.1M | 0.652% | 2026-02-24 | J.P. Morgan Securities LLC |
| 2026-02-20 | Kastelein Johannes Jacob PieterOfficer, Director | 45K | $1.6M | 0.040% | 2026-02-20 | ABN AMRO |
| 2026-01-20 | Mayur SomaiyaAffiliate | 200K | $6.3M | 0.176% | 2026-01-20 | J.P. Morgan Securities LLC |
| 2026-01-07 | Michael Davidsonaffiliate | 12K | $411K | 0.010% | 2026-01-07 | J.P. Morgan Securities LLC |
| 2026-01-06 | Douglas F KlingAffiliate | 300K | $10.0M | 0.265% | 2026-01-06 | J.P. Morgan Securities LLC |
| 2026-01-05 | Mayur Ian Somaiyaaffiliate | 5K | $170K | 0.005% | 2026-01-05 | J.P. Morgan Securities LLC |
| 2026-01-05 | Louise Kooijaffiliate | 3K | $88K | 0.002% | 2026-01-05 | J.P. Morgan Securities LLC |
| 2026-01-05 | Johannes KasteleinAffiliate | 6K | $199K | 0.005% | 2026-01-05 | J.P. Morgan Securities LLC |
| 2025-12-23 | Louise KooijOfficer | 290K | $10.6M | 0.256% | 2025-12-23 | J.P. Morgan Securities LLC |
| 2025-12-02 | Bain Capital Life Sciences Fund II, L.P.Former Affiliate | 267K | $10.3M | 0.236% | 2025-12-02 | Goldman Sachs & Co. LLC |
| 2025-12-02 | BCLS II Investco, LPFormer Affiliate | 4.5M | $172.5M | 3.969% | 2025-12-02 | Goldman Sachs & Co. LLC |
| 2025-12-02 | BCIP Life Sciences Associates, LPFormer Affiliate | 33K | $1.2M | 0.029% | 2025-12-02 | Goldman Sachs & Co. LLC |
Large holders (13D and 13G)
One row per reporting person with its latest filing, newest first. JSON12 holders report 5% or more of NAMS in their latest filing, 9 on Schedule 13D (active intent). The largest reported stake is Capital World Investors at 10.4% of the class (12,188,377 shares), filed 2026-06-04 for an event on 2026-05-29.
| Filed | Form | Holder | Shares | Of class | Event |
|---|---|---|---|---|---|
| 2026-09-22 | 13D/Ano. 7 | FHMLSP, L.P.partnership | 10.4M | 8.7% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | FHMLSP, L.L.C.other entity | 10.4M | 8.7% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | Frazier Life Sciences Public Fund, L.P.partnership | 10.4M | 8.7% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | Patrick J. Heronindividual | 7.3M | 6.1% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | James N. Topperindividual | 7.3M | 6.1% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | FHMLS X, L.L.C.other entity | 7.3M | 6.1% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | FHMLS X, L.P.partnership | 7.3M | 6.1% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | Frazier Life Sciences X, L.P.partnership | 7.3M | 6.1% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | Frazier Lifesciences Sponsor LLCother entity | 4.0M | 3.3% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | Frazier Life Sciences XI, L.P.partnership | 1.3M | 1.1% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | FHMLS XI, L.L.C.other entity | 1.3M | 1.1% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | FHMLS XI, L.P.partnership | 1.3M | 1.1% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | FHMLS XII, L.P.partnership | 365K | 0.3% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | Frazier Life Sciences XII, L.P.partnership | 365K | 0.3% | 2026-09-18 |
| 2026-09-22 | 13D/Ano. 7 | FHMLS XII, L.L.C.other entity | 365K | 0.3% | 2026-09-18 |
| 2026-08-06 | 13G/Ano. 2 | Abigail P. Johnsonindividual | 10.3M | 8.8% | 2026-06-30 |
| 2026-08-06 | 13G/Ano. 2 | FMR LLCparent holding company | 10.3M | 8.8% | 2026-06-30 |
| 2026-06-04 | 13G/Ano. 3 | Capital World Investorsinvestment adviser | 12.2M | 10.4% | 2026-05-29 |
| 2026-05-14 | 13D/Ano. 6 | BCLS Fund III Investments, LPpartnership | 2.1M | 1.8% | 2026-05-12 |
| 2026-05-14 | 13D/Ano. 6 | Bain Capital Life Sciences Opportunities III, LPpartnership | 1.3M | 1.1% | 2026-05-12 |
| 2026-05-14 | 13D/Ano. 6 | BCLS II Equity Opportunities, LPpartnership | 376K | 0.3% | 2026-05-12 |
| 2026-05-14 | 13D/Ano. 6 | BCLS II Investco, LPpartnership | 114K | 0.1% | 2026-05-12 |
| 2026-05-14 | 13D/Ano. 6 | Bain Capital Life Sciences Fund II, L.P.partnership | 89K | 0.1% | 2026-05-12 |
| 2026-05-14 | 13D/Ano. 6 | BCIP Life Sciences Associates, LPpartnership | 11K | 0.0% | 2026-05-12 |
| 2026-02-17 | 13G/Ano. 3 | Shabet Rose Sharonindividual | 4.2M | 3.7% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 3 | VIKING GLOBAL INVESTORS LPpartnership | 4.2M | 3.7% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 3 | Viking Global Opportunities Parent GP LLCother entity | 4.2M | 3.7% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 3 | HALVORSEN OLE ANDREASindividual | 4.2M | 3.7% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 3 | Ott David C.individual | 4.2M | 3.7% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 3 | Viking Global Opportunities GP LLCother entity | 2.8M | 2.5% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 3 | Viking Global Opportunities Portfolio GP LLCother entity | 2.8M | 2.5% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 3 | Viking Global Opportunities Illiquid Investments Sub-Master LPpartnership | 2.8M | 2.5% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 3 | Viking Global Opportunities Drawdown GP LLCother entity | 1.4M | 1.2% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 3 | Viking Global Opportunities Drawdown Portfolio GP LLCother entity | 1.4M | 1.2% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 3 | Viking Global Opportunities Drawdown (Aggregator) LPpartnership | 1.4M | 1.2% | 2025-12-31 |
| 2025-09-30 | 13D/Ano. 5 | ForGrowth NAP B.V.other entity | 9.3M | 8.3% | 2025-09-26 |
| 2025-09-30 | 13D/Ano. 5 | Forbion Capital Fund IV Cooperatief U.A.other entity | 4.7M | 4.1% | 2025-09-26 |
| 2025-09-30 | 13D/Ano. 5 | Forbion IV Management B.V.other entity | 4.7M | 4.1% | 2025-09-26 |
| 2025-09-30 | 13D/Ano. 5 | Forbion Growth Opportunities Fund I Cooperatief U.A.other entity | 4.6M | 4.1% | 2025-09-26 |
| 2025-09-30 | 13D/Ano. 5 | Forbion Growth Management B.V.other entity | 4.6M | 4.1% | 2025-09-26 |
13F holders
Tracked managers holding NAMS at their latest 13F. JSON8 of the 30 tracked managers held NAMS at their latest 13F, $296.4M in total at quarter-end prices. Viking Global Investors is the largest at $142.5M (0.4% of its portfolio) as of 2026-06-30. Over the prior quarter 5 added shares and 1 cut.
| Fund | Quarter | Shares | Value | Of portfolio | Change in shares |
|---|---|---|---|---|---|
| Viking Global Investors | 2026-06-30 | 4.2M | $142.5M | 0.41% | 0 |
| Duquesne Family Office | 2026-06-30 | 3.1M | $104.0M | 2.00% | 0 |
| Citadel Advisors | 2026-06-30 | 646K | $21.9M | 0.00% | -66K |
| Millennium Management | 2026-06-30 | 502K | $17.0M | 0.01% | +198K |
| Point72 Asset Management | 2026-06-30 | 169K | $5.7M | 0.01% | new |
| D. E. Shaw & Co. | 2026-06-30 | 121K | $4.1M | 0.00% | new |
| AQR Capital Management | 2026-06-30 | 23K | $769K | 0.00% | +12K |
| Two Sigma Investments | 2026-06-30 | 12K | $407K | 0.00% | new |
Only the 30 tracked managers on the funds hub; a 13F reports long positions in US listed stock at quarter end, 45 days late, and says nothing about shorts or positions sold since.
What this page is
NewAmsterdam Pharma in the regulatory record
Regulators publish company data in separate files that never sit next to each other: FINRA's twice-monthly short interest, its daily short sale volume, the SEC's fails-to-deliver counts, and each insider's Form 4. A company page puts those series for one ticker on one URL, with planned sales, large holders, 13F holders and financials beside them, so the short position, the daily flow, the settlement fails and what insiders are doing can be read together.
Each section has its own history table, a one-line summary of the latest figures and its own JSON and CSV links, and says when its source last updated.
This page follows NewAmsterdam Pharma (NAMS), SEC CIK 1936258, listed on Nasdaq, classified by the SEC as pharmaceutical preparations. The cross-market tables live on the short interest and insider transactions hubs.
Source and updates
- Short interest
- FINRA consolidated short interestSource: FINRA.Twice a month, about eight business days after settlement. Latest 2026-10-15.JSON and CSV
- Daily short volume
- FINRA Reg SHO daily filesSource: FINRA.Every trading day, the morning after FINRA posts it. Latest 2026-11-02.JSON and CSV
- Fails to deliver
- SEC fails-to-deliver dataSource: SEC.Twice a month, a few weeks after the half month ends. Latest 2026-10-07.JSON and CSV
- Planned sales
- SEC EDGAR Form 144Source: SEC.New notices appear shortly after the SEC posts them; a notice is filed on or before the sale. Latest 2026-03-11.JSON and CSV
- Large holders
- SEC EDGAR Schedule 13D and 13GSource: SEC.New filings appear shortly after the SEC posts them. A 13D is due within five business days of crossing 5%; a 13G follows the passive schedule. Latest 2026-09-22.JSON and CSV
- 13F holders
- SEC EDGAR Form 13F-HRSource: SEC.Quarterly, filed within 45 days of quarter end; 30 tracked managers. Latest 2026-06-30.JSON and CSV
- Earnings dates
- SEC EDGAR 8-K filings (Item 2.02)Source: SEC.Twice a day. Reported dates come from the company's 8-K filings; the next date is marked as an estimate until the 8-K arrives. Latest 2026-08-05.JSON and CSV
- Insider trades
- SEC EDGAR Form 4Source: SEC.New filings appear shortly after the SEC posts them; they're due two business days after the trade. Latest 2026-09-30.JSON and CSV
- Company record
- EDGAR filing index for CIK 1936258Ticker, name and exchange from the SEC's company list, refreshed weekly.
- Rate limits
- 10 requests a minute without a key, 30 with a free key from a free account.
How to read it
- Read the position against the flow: rising short interest with a high daily short share is new shorting; rising short interest with a normal short share is old shorts holding on.
- Insider buys next to a large short position are rare and stand out; insider sells next to one are common and mean little.
- Fails to deliver matter relative to the float, not in absolute shares; a million failed shares in a mega cap is noise.
Analysis of what the data shows, not advice. XOOMAR does not recommend buying, selling or holding anything.
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Datasets
Frequently Asked Questions
How much of NAMS is sold short?
14,110,048 shares were held short at the 2026-10-15 settlement, 10.6 days of average volume. FINRA publishes the next count about eight business days after the 15th and the last business day of the month.
What is NAMS's daily short volume?
On 2026-11-02, 455,398 of the 973,283 NAMS shares reported to FINRA were sold short, 46.8% of the day's reported volume. Short volume is a flow for one day, not a position.
Does NAMS have fails to deliver?
The SEC's latest file shows 442 NAMS shares failed to deliver at settlement 2026-10-07. Fails are reported per settlement date and published twice a month with a lag.
Are NAMS insiders buying or selling?
Over the last 90 days NAMS insiders reported 1 open-market buy ($227K) against 3 sells ($4.7M), so the dollar flow leans toward selling. Latest filing: Kastelein Johannes Jacob Pieter (Chief Scientific Officer) on 2026-09-30.
Have NAMS insiders filed to sell?
16 Form 144 notices on file for NAMS worth $267.9M at the prices reported; 0 in the last 90 days worth $0. Latest: Louis G. Lange filed on 2026-03-11 to sell 44,619 shares ($1.4M) from 2026-03-11.
Who owns 5% or more of NAMS?
12 holders report 5% or more of NAMS in their latest filing, 9 on Schedule 13D (active intent). The largest reported stake is Capital World Investors at 10.4% of the class (12,188,377 shares), filed 2026-06-04 for an event on 2026-05-29.
Which tracked 13F managers own NAMS?
8 of the 30 tracked 13F managers held NAMS shares at their latest filing, $296.4M in all. The largest: Andreas Halvorsen's Viking Global Investors (4.2M shares, $142.5M), Stanley Druckenmiller's Duquesne Family Office (3.1M shares, $104.0M), Ken Griffin's Citadel Advisors (646K shares, $21.9M), Izzy Englander's Millennium Management (502K shares, $17.0M), Steve Cohen's Point72 Asset Management (169K shares, $5.7M), D. E. Shaw & Co. (121K shares, $4.1M). The table above lists all 8.
Data on this page is provided for informational purposes only and is not financial advice. See our editorial policy.