Rock Springs Capital Management LP
Position in MBX — MBX Biosciences, Inc.
CIK 1595725
Baltimore, MD
Position in MBX
as of Jun 30, 2026
· filed Aug 14, 2026
Position Value
$16,461,633
+$7,865,819 QoQ
Shares Held
298,218
+3.6% QoQ
Ownership
0.619%
of shares outstanding
% of Portfolio
0.80%
of 13F equity value
Holder Rank
#30
of 172 holders
Holding Since
Sep 2025
4 quarters on record
Voting authority
Sole 100%
Shared 0%
None 0%
Common Shares in MBX Over Time
Shares Held
Position Value (USD)
Position in Biotechnology
Healthcare · as of Jun 30, 2026Rock Springs Capital Management LP holds $1,502,002,537 across 70 Biotechnology names. MBX ranks #28 (1.1% of the industry book) .
| # | Ticker | Company | Shares | Value (USD) | Open |
|---|---|---|---|---|---|
| 1 | RVMD |
Revolution Medicines, Inc.
|
1,105,210 | $206,983,728 | |
| 2 | TVTX |
Travere Therapeutics, Inc.
|
2,179,069 | $123,792,909 | |
| 3 | MDGL |
Madrigal Pharmaceuticals, Inc.
|
174,999 | $93,965,713 | |
| 4 | MIRM |
Mirum Pharmaceuticals, Inc.
|
798,145 | $93,438,835 | |
| 5 | RYTM |
Rhythm Pharmaceuticals, Inc.
|
692,598 | $76,899,155 | |
| 6 | KYMR |
Kymera Therapeutics, Inc.
|
453,156 | $51,963,398 | |
| 7 | ARGX |
Argenx SE
|
52,750 | $48,939,867 | |
| 8 | ASND |
Ascendis Pharma A/S
|
168,750 | $45,009,000 |
All Filings in MBX
Export CSV
4 filing rows on record
| Report Date | Value (USD) | Shares | Type | Discretion | Filed | |
|---|---|---|---|---|---|---|
| 2026-06-30 | $16,461,633 | 298,218 | Shares | Sole | 2026-08-14 | |
| 2026-03-31 | $8,595,814 | 287,967 | Shares | Sole | 2026-05-15 | |
| 2025-12-31 | $8,913,960 | 282,624 | Shares | Sole | 2026-02-17 | |
| 2025-09-30 | $4,945,920 | 282,624 | Shares | Sole | 2025-11-14 | |
| No filing history on record for this holder in this stock. | ||||||