WESTFIELD CAPITAL MANAGEMENT CO LP
Position in NAMS — NewAmsterdam Pharma Co N.V.
CIK 1177719
BOSTON, MA
Position in NAMS
as of Jun 30, 2026
· filed Aug 12, 2026
Position Value
$52,071,036
-$18,444,209 QoQ
Shares Held
1,536,472
-30.3% QoQ
Ownership
1.29%
of shares outstanding
% of Portfolio
0.17%
of 13F equity value
Holder Rank
#18
of 198 holders
Holding Since
Mar 2026
2 quarters on record
Voting authority
Sole 92%
Shared 0%
None 8%
Common Shares in NAMS Over Time
Shares Held
Position Value (USD)
Position in Biotechnology
Healthcare · as of Jun 30, 2026WESTFIELD CAPITAL MANAGEMENT CO LP holds $3,083,455,798 across 23 Biotechnology names. NAMS ranks #15 (1.7% of the industry book) .
| # | Ticker | Company | Shares | Value (USD) | Open |
|---|---|---|---|---|---|
| 1 | ASND |
Ascendis Pharma A/S
|
4,798,267 | $1,279,793,774 | |
| 2 | RYTM |
Rhythm Pharmaceuticals, Inc.
|
2,208,595 | $245,220,302 | |
| 3 | ABVX |
Abivax S.A.
|
1,309,825 | $174,547,279 | |
| 4 | INSM |
INSMED Inc
|
1,629,561 | $173,743,793 | |
| 5 | PTCT |
Ptc Therapeutics, Inc.
|
1,956,156 | $159,563,644 | |
| 6 | PCVX |
Vaxcyte, Inc.
|
2,472,428 | $143,722,239 | |
| 7 | LEGN |
Legend Biotech Corp
|
4,430,063 | $127,940,219 | |
| 8 | RVMD |
Revolution Medicines, Inc.
|
600,821 | $112,521,756 |
All Filings in NAMS
Export CSV
2 filing rows on record
| Report Date | Value (USD) | Shares | Type | Discretion | Filed | |
|---|---|---|---|---|---|---|
| 2026-06-30 | $52,071,036 | 1,536,472 | Shares | Sole | 2026-08-12 | |
| 2026-03-31 | $70,515,245 | 2,202,913 | Shares | Sole | 2026-05-11 | |
| No filing history on record for this holder in this stock. | ||||||