Rock Springs Capital Management LP
Position in RYTM — Rhythm Pharmaceuticals, Inc.
CIK 1595725
Baltimore, MD
Position in RYTM
as of Mar 31, 2026
· filed May 15, 2026
Position Value
$59,987,383
-$14,406,487 QoQ
Shares Held
689,748
-0.8% QoQ
Ownership
1.01%
of shares outstanding
% of Portfolio
3.55%
of 13F equity value
Holder Rank
—
not a current holder
Holding Since
Mar 2020
25 quarters on record
Voting authority
Sole 100.ToString("F0")%
Shared 0.ToString("F0")%
None 0.ToString("F0")%
Common Shares in RYTM 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. RYTM ranks #5 (4.8% 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.
This page
|
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 RYTM
Export CSV
25 filing rows on record
| Report Date | Value (USD) | Shares | Type | Discretion | Filed | |
|---|---|---|---|---|---|---|
| 2026-03-31 | $59,987,383 | 689,748 | Shares | Sole | 2026-05-15 | |
| 2025-12-31 | $74,393,870 | 695,010 | Shares | Sole | 2026-02-17 | |
| 2025-09-30 | $72,420,130 | 717,102 | Shares | Sole | 2025-11-14 | |
| 2025-06-30 | $54,416,258 | 861,153 | Shares | Sole | 2025-08-14 | |
| 2025-03-31 | $44,186,938 | 834,188 | Shares | Sole | 2025-05-15 | |
| 2024-12-31 | $65,088,953 | 1,162,718 | Shares | Sole | 2025-02-14 | |
| 2024-09-30 | $64,339,792 | 1,228,093 | Shares | Sole | 2024-11-14 | |
| 2024-06-30 | $52,577,042 | 1,280,493 | Shares | Sole | 2024-08-14 | |
| 2024-03-31 | $65,986,953 | 1,522,893 | Shares | Sole | 2024-05-15 | |
| 2023-12-31 | $70,007,391 | 1,522,893 | Shares | Sole | 2024-02-14 | |
| 2023-09-30 | $36,614,044 | 1,597,123 | Shares | Sole | 2023-11-14 | |
| 2023-06-30 | $26,336,558 | 1,597,123 | Shares | Sole | 2023-08-14 | |
| 2023-03-31 | $28,492,674 | 1,597,123 | Shares | Sole | 2023-05-15 | |
| 2022-12-31 | $51,276,388 | 1,760,865 | Shares | Sole | 2023-02-14 | |
| 2022-09-30 | $43,141,192 | 1,760,865 | Shares | Sole | 2022-11-14 | |
| 2022-06-30 | $5,823,686 | 1,403,298 | Shares | Sole | 2022-08-15 | |
| 2022-03-31 | $14,250,539 | 1,237,026 | Shares | Sole | 2022-05-16 | |
| 2021-12-31 | $6,259,256 | 627,180 | Shares | Sole | 2022-02-14 | |
| 2021-09-30 | $7,995,070 | 612,180 | Shares | Sole | 2021-11-15 | |
| 2021-06-30 | $11,870,962 | 606,280 | Shares | Sole | 2021-08-16 | |
| 2021-03-31 | $12,746,685 | 599,280 | Shares | Sole | 2021-05-17 | |
| 2020-12-31 | $14,577,778 | 490,339 | Shares | Sole | 2021-02-16 | |
| 2020-09-30 | $10,056,743 | 464,086 | Shares | Sole | 2020-11-16 | |
| 2020-06-30 | $11,420,075 | 512,111 | Shares | Sole | 2020-08-14 | |
| 2020-03-31 | $7,610,000 | 500,000 | Shares | Sole | 2020-05-15 | |
| No filing history on record for this holder in this stock. | ||||||