Rock Springs Capital Management LP's Q2 2023 13F: 7 new positions, 4 exits
Form 13F-HR for the quarter ended Jun 30, 2023 · filed Aug 14, 2023 · 119 reported positions · accession 0001172661-23-003005
What changed this quarter
| Activity | Security | Weight before | Weight now | Change | Shares | Shares % |
|---|---|---|---|---|---|---|
| Exited | PROMETHEUS BIOSCIENCES INC (RXDX) | 2.6% | — | −2.6 pts | −1.03M sh | −100% |
| Reduced | MADRIGAL PHARMACEUTICALS INC (MDGL) | 2.0% | 1.1% | −0.9 pts | −149K sh | −43% |
| Reduced | HORIZON THERAPEUTICS PUB L (HZNP) | 1.9% | 1.2% | −0.7 pts | −245K sh | −33% |
| Reduced | PENUMBRA INC (PEN) | 2.9% | 3.0% | +0.1 pts | −67,500 sh | −16% |
| Increased | HUMANA INC (HUM) | 5.0% | 5.0% | +0.1 pts | +43,500 sh | +10% |
| Exited | AMRYT PHARMA PLC (AMYT) | 0.5% | — | −0.5 pts | −1.33M sh | −100% |
| Reduced | UNITEDHEALTH GROUP INC (UNH) | 3.1% | 2.6% | −0.4 pts | −40,000 sh | −15% |
| New | BOSTON SCIENTIFIC CORP (BSX) | — | 0.3% | +0.3 pts | +268K sh | new |
| New | MERUS N V (MRUS) | — | 0.3% | +0.3 pts | +479K sh | new |
| Reduced | ALIGN TECHNOLOGY INC (ALGN) | 2.0% | 1.8% | −0.1 pts | −30,350 sh | −12% |
| Reduced | BIOMEA FUSION INC (BMEA) | 1.0% | 0.4% | −0.5 pts | −460K sh | −35% |
| Increased | BLUEPRINT MEDICINES CORP (BPMC) | 2.2% | 3.3% | +1.1 pts | +154K sh | +8% |
| Exited | VERVE THERAPEUTICS INC (VERV) | 0.2% | — | −0.2 pts | −559K sh | −100% |
| Increased | AGILON HEALTH INC (AGL) | 4.5% | 3.4% | −1.1 pts | +400K sh | +5% |
| Reduced | BIOHAVEN LTD (BHVN) | 0.2% | 0.2% | 0.0 pts | −284K sh | −41% |
| Increased | NEUROCRINE BIOSCIENCES INC (NBIX) | 2.9% | 2.9% | −0.1 pts | +69,400 sh | +6% |
| Reduced | IDEXX LABS INC (IDXX) | 2.5% | 2.3% | −0.2 pts | −13,000 sh | −6% |
| Increased | INSULET CORP (PODD) | 4.1% | 3.8% | −0.3 pts | +22,250 sh | +4% |
| Increased | KYMERA THERAPEUTICS INC (KYMR) | 0.9% | 0.8% | −0.1 pts | +259K sh | +21% |
| Reduced | ANAPTYSBIO INC (ANAB) | 0.3% | 0.2% | −0.1 pts | −235K sh | −41% |
| Increased | ZAI LAB LTD (ZLAB) | 0.8% | 0.8% | 0.0 pts | +163K sh | +15% |
| Increased | AKERO THERAPEUTICS INC (AKRO) | 1.3% | 1.7% | +0.4 pts | +96,500 sh | +7% |
| Reduced | CHINOOK THERAPEUTICS INC (KDNY) | 0.3% | 0.4% | +0.1 pts | −111K sh | −22% |
| New | KRYSTAL BIOTECH INC (KRYS) | — | 0.1% | +0.1 pts | +34,901 sh | new |
| Increased | ABCAM PLC (ABCZF) | 0.7% | 1.4% | +0.7 pts | +163K sh | +7% |
| Increased | TRAVERE THERAPEUTICS INC (TVTX) | 0.7% | 0.6% | −0.1 pts | +251K sh | +20% |
| Increased | ACADIA HEALTHCARE COMPANY IN (ACHC) | 1.5% | 1.7% | +0.2 pts | +47,132 sh | +5% |
| Increased | ACCOLADE INC (ACCD) | 0.9% | 0.9% | 0.0 pts | +275K sh | +11% |
| Increased | NEVRO CORP (NVRO) | 0.9% | 0.7% | −0.2 pts | +134K sh | +12% |
| New | LEAP THERAPEUTICS INC (CYPH) | — | 0.1% | +0.1 pts | +1.07M sh | new |
| Reduced | GAMIDA CELL LTD (GMDA) | 0.0% | 0.0% | 0.0 pts | −1.63M sh | −70% |
| New | ACELYRIN INC (SLRN) | — | 0.1% | +0.1 pts | +142K sh | new |
| New | BLACK DIAMOND THERAPEUTICS I (BDTX) | — | 0.1% | +0.1 pts | +563K sh | new |
| Reduced | MERSANA THERAPEUTICS INC (MRSN) | 0.4% | 0.3% | −0.1 pts | −701K sh | −17% |
| Increased | DISC MEDICINE INC (IRON) | 0.2% | 0.4% | +0.2 pts | +50,000 sh | +16% |
| Increased | ULTRAGENYX PHARMACEUTICAL IN (RARE) | 1.3% | 1.5% | +0.2 pts | +47,868 sh | +4% |
| New | IMMUNOGEN INC (IMGN) | — | 0.1% | +0.1 pts | +113K sh | new |
| Increased | MIRATI THERAPEUTICS INC (MRTX) | 0.9% | 1.0% | 0.0 pts | +56,386 sh | +5% |
| Reduced | SAREPTA THERAPEUTICS INC (SRPT) | 1.5% | 1.2% | −0.3 pts | −17,500 sh | −4% |
| Increased | AMYLYX PHARMACEUTICALS INC (AMLX) | 1.0% | 0.8% | −0.2 pts | +91,800 sh | +6% |
| Increased | AZENTA INC (AZTA) | 0.5% | 0.5% | +0.1 pts | +38,700 sh | +9% |
| Reduced | INVITAE CORP (NVTA) | 0.1% | 0.0% | −0.1 pts | −1.59M sh | −49% |
| Increased | IMMUNOCORE HLDGS PLC (IMCR) | 3.5% | 4.3% | +0.8 pts | +26,748 sh | +1% |
| Exited | LEAP THERAPEUTICS INC (LPTX) | 0.0% | — | 0.0 pts | −4.66M sh | −100% |
| Increased | EDAP TMS S A (EDAP) | 0.3% | 0.3% | 0.0 pts | +156K sh | +15% |
| Increased | INOZYME PHARMA INC (INZY) | 0.4% | 0.5% | 0.0 pts | +213K sh | +7% |
| Increased | BIOCRYST PHARMACEUTICALS INC (BCRX) | 0.5% | 0.4% | 0.0 pts | +163K sh | +7% |
| Increased | MEREO BIOPHARMA GROUP PLC (MREO) | 0.1% | 0.2% | +0.1 pts | +797K sh | +13% |
| Increased | AGIOS PHARMACEUTICALS INC (AGIO) | 1.5% | 1.8% | +0.4 pts | +24,562 sh | +1% |
| Increased | MIRUM PHARMACEUTICALS INC (MIRM) | 1.0% | 1.1% | +0.1 pts | +25,000 sh | +1% |
The 50 largest of 62 changes, by size of the trade. Full holdings for this quarter.
Reported by the fund in its Form 13F filed with the SEC; holdings are as of the quarter-end report date and may have changed since. For informational purposes only — not investment advice or a recommendation to buy or sell any security. FilingExplorer is not affiliated with or endorsed by this fund. How this brief is compiled
Top 10 positions — 34.4% of the equity book
Changes in the top 10 this quarter: BPMC entered · RXDX left
| # | Security | Weight before | Weight now | |
|---|---|---|---|---|
| 1 | HUMANA INC (HUM) | 5.0% | 5.0% | |
| 2 | IMMUNOCORE HLDGS PLC (IMCR) | 3.5% | 4.3% | |
| 3 | INSULET CORP (PODD) | 4.1% | 3.8% | |
| 4 | AGILON HEALTH INC (AGL) | 4.5% | 3.4% | |
| 5 | BLUEPRINT MEDICINES CORP (BPMC) | 2.2% | 3.3% | Entered the top 10 |
| 6 | ARGENX SE (ARGX) | 3.1% | 3.3% | |
| 7 | PENUMBRA INC (PEN) | 2.9% | 3.0% | |
| 8 | NEUROCRINE BIOSCIENCES INC (NBIX) | 2.9% | 2.9% | |
| 9 | EVOLENT HEALTH INC (EVH) | 3.0% | 2.7% | |
| 10 | UNITEDHEALTH GROUP INC (UNH) | 3.1% | 2.6% | |
| — | PROMETHEUS BIOSCIENCES INC (RXDX) | 2.6% | 0.0% | Left the top 10 |
Weights are each position's reported value as a share of the fund's reported equity positions (options and principal-amount holdings excluded).
Option positions (puts and calls)
Reported separately from the positions above. The value a 13F reports for an option is that of the underlying shares, not the option itself.
| Activity | Security | Type | Shares before | Shares now | Reported value |
|---|---|---|---|---|---|
| Exited | 89BIO INC (ETNB) | Call | 165K | 0 | $0 |