Position in ZLAB
as of Mar 31, 2026
· filed May 15, 2026
Position Value
$15,324,638
+$1,008,967 QoQ
Shares Held
814,707
+0.4% QoQ
Ownership
0.056%
of shares outstanding
% of Portfolio
0.91%
of 13F equity value
Holder Rank
—
not a current holder
Holding Since
Mar 2020
25 quarters on record
Voting authority
Sole 100%
Shared 0%
None 0%
Common Shares in ZLAB Over Time
Shares Held
Position Value (USD)
Position in Biotechnology
Healthcare · as of Mar 31, 2026Rock Springs Capital Management LP holds $1,246,050,197 across 66 Biotechnology names. ZLAB ranks #28 (1.2% of the industry book) .
| # | Ticker | Company | Shares | Value (USD) | Open |
|---|---|---|---|---|---|
| 1 | RVMD |
Revolution Medicines, Inc.
|
1,209,465 | $117,620,471 | |
| 2 | MDGL |
Madrigal Pharmaceuticals, Inc.
|
170,999 | $89,512,846 | |
| 3 | MIRM |
Mirum Pharmaceuticals, Inc.
|
811,294 | $74,947,339 | |
| 4 | ARGX |
Argenx SE
|
98,500 | $71,929,625 | |
| 5 | RYTM |
Rhythm Pharmaceuticals, Inc.
|
689,748 | $59,987,383 | |
| 6 | INSM |
INSMED Inc
|
314,300 | $51,394,336 | |
| 7 | ASND |
Ascendis Pharma A/S
|
194,000 | $44,373,620 | |
| 8 | XENE |
Xenon Pharmaceuticals Inc.
|
763,020 | $44,369,613 |
All Filings in ZLAB
Export CSV
25 filing rows on record
| Report Date | Value (USD) | Shares | Type | Discretion | Filed | |
|---|---|---|---|---|---|---|
| 2026-03-31 | $15,324,638 | 814,707 | Shares | Sole | 2026-05-15 | |
| 2025-12-31 | $14,315,671 | 811,546 | Shares | Sole | 2026-02-17 | |
| 2025-09-30 | $26,813,530 | 791,193 | Shares | Sole | 2025-11-14 | |
| 2025-06-30 | $30,472,578 | 871,392 | Shares | Sole | 2025-08-14 | |
| 2025-03-31 | $32,691,954 | 904,592 | Shares | Sole | 2025-05-15 | |
| 2024-12-31 | $34,186,776 | 1,305,337 | Shares | Sole | 2025-02-14 | |
| 2024-09-30 | $31,760,346 | 1,315,673 | Shares | Sole | 2024-11-14 | |
| 2024-06-30 | $22,492,139 | 1,297,873 | Shares | Sole | 2024-08-14 | |
| 2024-03-31 | $20,779,910 | 1,297,123 | Shares | Sole | 2024-05-15 | |
| 2023-12-31 | $31,074,838 | 1,137,023 | Shares | Sole | 2024-02-14 | |
| 2023-09-30 | $30,072,029 | 1,237,023 | Shares | Sole | 2023-11-14 | |
| 2023-06-30 | $33,897,789 | 1,222,423 | Shares | Sole | 2023-08-14 | |
| 2023-03-31 | $35,245,622 | 1,059,700 | Shares | Sole | 2023-05-15 | |
| 2022-12-31 | $32,532,790 | 1,059,700 | Shares | Sole | 2023-02-14 | |
| 2022-09-30 | $40,780,080 | 1,192,400 | Shares | Sole | 2022-11-14 | |
| 2022-06-30 | $42,167,412 | 1,215,900 | Shares | Sole | 2022-08-15 | |
| 2022-03-31 | $53,035,482 | 1,205,900 | Shares | Sole | 2022-05-16 | |
| 2021-12-31 | $74,206,995 | 1,180,700 | Shares | Sole | 2022-02-14 | |
| 2021-09-30 | $113,584,072 | 1,077,750 | Shares | Sole | 2021-11-15 | |
| 2021-06-30 | $179,467,860 | 1,014,000 | Shares | Sole | 2021-08-16 | |
| 2021-03-31 | $124,556,905 | 933,500 | Shares | Sole | 2021-05-17 | |
| 2020-12-31 | $115,702,030 | 854,899 | Shares | Sole | 2021-02-16 | |
| 2020-09-30 | $68,492,740 | 823,527 | Shares | Sole | 2020-11-16 | |
| 2020-06-30 | $66,791,893 | 813,246 | Shares | Sole | 2020-08-14 | |
| 2020-03-31 | $38,610,000 | 750,000 | Shares | Sole | 2020-05-15 | |
| No filing history on record for this holder in this stock. | ||||||