Rock Springs Capital Portfolio
13F Holdings & Position Changes — Last filed May 15, 2026
13F Holdings & Position Changes — Last filed May 15, 2026
Concentrated long/short healthcare fund focused on fundamental research. Rock Springs takes conviction-weighted positions based on deep pipeline analysis, therapeutic area expertise, and a willingness to be contrarian when the science supports it.
Rock Springs Capital is a $6B biotech-focused hedge fund managed by Graham McPhail. As of their latest 13F filing (Q1 2026), the fund holds 94 positions worth $1.7B. This quarter they initiated 6 new positions and exited 76. Their largest holding is RVMD ($117.6M).
Rock initiated 6 new positions and increased 40 this quarter. Portfolio shrank -5.6% to $1.7B. 646 upcoming catalysts across holdings.
Portfolio Value (13F)
$1.7B
Holdings
94
Top 10 Concentration
42.3%
QoQ Change
-5.6%
Turnover
3.4%
Portfolio Value Trend
Be first to know when Rock Springs Capital files next quarter
Get an email the moment new buys, exits, and conviction changes hit. Free 14-day trial.
| # | Ticker | Company | Change | Value | % of Portfolio | SI % Float ? | Trend |
|---|---|---|---|---|---|---|---|
| 1 | RVMD | Revolution Medicines Inc. | Decreased | $117.6M | 6.92% | 6.1% | |
| 2 | RYTM | Rhythm Pharmaceuticals Inc. | Increased | $90.9M | 5.35% | 11.8% | |
| 3 | LLY | Eli Lilly & Co | Decreased↓2Q | $90.8M | 5.34% | 1.1% | |
| 4 | MDGL | Madrigal Pharmaceuticals Inc. | Increased↑2Q | $89.5M | 5.27% | 19.3% | |
| 5 | MIRM | Mirum Pharmaceuticals Inc. | Increased↑2Q | $74.9M | 4.41% | 14.1% | |
| 6 | ARGX | argenx SE | Decreased↓5Q | $71.9M | 4.23% | 3.3% | |
| 7 | INSM | Insmed Incorporated | Decreased↓3Q | $51.4M | 3.02% | 9.9% | |
| 8 | ASND | Ascendis Pharma A/S | Decreased↓3Q | $44.4M | 2.61% | 3.6% | |
| 9 | XENE | Xenon Pharmaceuticals Inc. | Decreased↓5Q | $44.4M | 2.61% | 4.6% | |
| 10 | TVTX | Travere Therapeutics Inc. | Decreased | $43.9M | 2.58% | 18.1% |
Share changes reflect active decisions. Value changes include price moves.
Track this fund’s next move
13F changes, conviction shifts, and catalyst alerts across all 20 specialist biotech funds — free Monday brief.
See all 94 holdings (you're viewing the top 10), plus 7 quarters of position history.
No charge for 14 days · Cancel anytime
Rock Springs Capital held 94 biotech stocks in their 13F portfolio this quarter. Their top positions include RVMD, RYTM, LLY, MDGL, MIRM. The full holdings table is available on BiotechEdge with position sizes, quarter-over-quarter changes, and AI analysis.
Rock Springs Capital's tracked biotech portfolio is worth $1.7B across 94 positions, with total assets under management of approximately $6B. Portfolio values are based on 13F filings with the SEC.
Rock Springs Capital initiated 6 new positions this quarter, including IRTC, MMED, SYK, IPSC, CVS and 1 more. They also increased 40 existing positions.
Rock Springs Capital fully exited 76 positions this quarter, including SWTX, AUPH, CERE, NMRA, ALLK and 71 more. They also trimmed 23 existing positions.
Concentrated long/short healthcare fund focused on fundamental research. Rock Springs takes conviction-weighted positions based on deep pipeline analysis, therapeutic area expertise, and a willingness to be contrarian when the science supports it.
Track specialist biotech funds, insider signals, and AI analysis
Start 14-Day Free Trial