undamentalytics Newsletter

Hedge fund

Rock Springs Capital Management LP

13F for the quarter to June 30, 2026, filed August 14, 2026 · SEC CIK 1595725

Reported value
$2.0bn
100% in companies we cover
Positions we cover
103
Largest RVMD 10.1%
Copy, a year
+6.4%
S&P 500 +13.7%
Copy Sharpe ratio
0.30
S&P 500 0.75

How copying its 13F would have done

$10.0k$20.0k$40.0k 2014201620182020202220242026 $50.9k$22.0k
CopyS&P 500 $10,000 copying Rock Springs Capital Management LP's filed holdings in companies we cover from February 21, 2014, buying on the first trading day after each 13F was filed and holding until the next, against the S&P 500 (total return). Marked weekly, log scale. Before costs and taxes; misses trading within each quarter and anything 13F does not show (shorts, cash, bonds, non-US holdings).

Biggest drop −45.5% (S&P 500 −31.8%); beta 1.03; alpha −5.7% a year (t = −1.27); last 12 months +8.2% against +12.1%.

Reported value by quarter

Rock Springs Capital Management LP: 13F reported value Total value of all positions in each quarter's 13F, as filed (values before 2023 were filed in thousands of dollars and are converted).
$0 $2T $4T $6T Reported value, 2013-12-31: $279.9M Reported value, 2014-03-31: $433.6M Reported value, 2014-06-30: $557.7M Reported value, 2014-09-30: $646.4M Reported value, 2014-12-31: $854.9M Reported value, 2015-03-31: $1.1B Reported value, 2015-06-30: $1.4B Reported value, 2015-09-30: $1.2B Reported value, 2015-12-31: $1.3B Reported value, 2016-03-31: $1.2B Reported value, 2016-06-30: $1.3B Reported value, 2016-09-30: $1.6B Reported value, 2016-12-31: $1.5B Reported value, 2017-03-31: $1.7B Reported value, 2017-06-30: $1.9B Reported value, 2017-09-30: $2.1B Reported value, 2017-12-31: $2.2B Reported value, 2018-03-31: $2.3B Reported value, 2018-06-30: $2.6B Reported value, 2018-09-30: $2.7B Reported value, 2018-12-31: $2.1B Reported value, 2019-03-31: $2.5B Reported value, 2019-06-30: $2.7B Reported value, 2019-09-30: $2.5B Reported value, 2019-12-31: $3.1B Reported value, 2020-03-31: $2.4B Reported value, 2020-06-30: $3.6B Reported value, 2020-09-30: $3.9B Reported value, 2020-12-31: $4.6B Reported value, 2021-03-31: $4.5B Reported value, 2021-06-30: $5B Reported value, 2021-09-30: $4.7B Reported value, 2021-12-31: $4.3B Reported value, 2022-03-31: $3.9B Reported value, 2022-06-30: $3.4B Reported value, 2022-09-30: $3.9B Reported value, 2022-12-31: $4.1T Reported value, 2023-03-31: $4.2B Reported value, 2023-06-30: $4.2B Reported value, 2023-09-30: $3.7B Reported value, 2023-12-31: $4B Reported value, 2024-03-31: $3.9B Reported value, 2024-06-30: $3.3B Reported value, 2024-09-30: $3.1B Reported value, 2024-12-31: $2.6B Reported value, 2025-03-31: $1.7B Reported value, 2025-06-30: $1.6B Reported value, 2025-09-30: $1.7B Reported value, 2025-12-31: $1.9B Reported value, 2026-03-31: $1.7B Reported value, 2026-06-30: $2B 2013-12-31 2016-06-30 2018-12-31 2021-06-30 2023-12-31 2026-06-30 $2B
View chart data
Period Reported value
2013-12-31 $279.9M
2014-03-31 $433.6M
2014-06-30 $557.7M
2014-09-30 $646.4M
2014-12-31 $854.9M
2015-03-31 $1.1B
2015-06-30 $1.4B
2015-09-30 $1.2B
2015-12-31 $1.3B
2016-03-31 $1.2B
2016-06-30 $1.3B
2016-09-30 $1.6B
2016-12-31 $1.5B
2017-03-31 $1.7B
2017-06-30 $1.9B
2017-09-30 $2.1B
2017-12-31 $2.2B
2018-03-31 $2.3B
2018-06-30 $2.6B
2018-09-30 $2.7B
2018-12-31 $2.1B
2019-03-31 $2.5B
2019-06-30 $2.7B
2019-09-30 $2.5B
2019-12-31 $3.1B
2020-03-31 $2.4B
2020-06-30 $3.6B
2020-09-30 $3.9B
2020-12-31 $4.6B
2021-03-31 $4.5B
2021-06-30 $5B
2021-09-30 $4.7B
2021-12-31 $4.3B
2022-03-31 $3.9B
2022-06-30 $3.4B
2022-09-30 $3.9B
2022-12-31 $4.1T
2023-03-31 $4.2B
2023-06-30 $4.2B
2023-09-30 $3.7B
2023-12-31 $4B
2024-03-31 $3.9B
2024-06-30 $3.3B
2024-09-30 $3.1B
2024-12-31 $2.6B
2025-03-31 $1.7B
2025-06-30 $1.6B
2025-09-30 $1.7B
2025-12-31 $1.9B
2026-03-31 $1.7B
2026-06-30 $2B

Holdings and moves

CompanyShare of portfolioValueSharesChange in shares
RVMDRevolution Medicines, Inc.10.10%$207.0m1.11M−8.6% Reduced
TVTXTravere Therapeutics, Inc.6.04%$123.8m2.18M+47.4% Added
LLYLilly (Eli)5.78%$118.4m98.7K0.0%
MDGLMadrigal Pharmaceuticals, Inc.4.59%$94.0m175.0K+2.3% Added
MIRMMirum Pharmaceuticals, Inc.4.56%$93.4m798.1K−1.6% Reduced
RYTMRhythm Pharmaceuticals, Inc.3.75%$76.9m692.6K+0.4%
KYMRKymera Therapeutics, Inc.2.54%$52.0m453.2K−8.8% Reduced
ARGXArgenx SE2.39%$48.9m52.8K−46.4% Reduced
ASNDAscendis Pharma A/s2.20%$45.0m168.8KNew
XENEXenon Pharmaceuticals Inc.2.02%$41.3m683.9K−10.4% Reduced
SRRKScholar Rock Holding Corp1.92%$39.3m715.5K−3.3% Reduced
INSMInsmed Inc1.89%$38.6m362.1K+15.2% Added
PENPenumbra Inc1.78%$36.5m115.8K−3.9% Reduced
GPCRStructure Therapeutics Inc.1.68%$34.4m640.3K0.0%
RAREUltragenyx Pharmaceutical Inc.1.58%$32.3m967.9K−20.6% Reduced
IRTCIrhythm Holdings, Inc.1.57%$32.1m269.6K+3.0% Added
ISRGIntuitive Surgical1.48%$30.4m76.5K−6.8% Reduced
AGLAgilon Health, Inc.1.37%$28.1m262.6K+1.0% Added
UNHUnitedHealth Group1.29%$26.5m63.8K+20.3% Added
CLDXCelldex Therapeutics, Inc.1.27%$26.0m699.1K+7.5% Added
ERASErasca, Inc.1.25%$25.7m1.40M+27.1% Added
NBIXNeurocrine Biosciences Inc1.19%$24.4m144.8K−3.8% Reduced
ELVNEnliven Therapeutics, Inc.1.15%$23.6m464.6K−43.8% Reduced
THCTenet Healthcare Corp1.14%$23.4m125.0K0.0%
DXCMDexcom1.13%$23.1m343.0K−3.5% Reduced
ACRSAclaris Therapeutics, Inc.1.12%$22.9m4.33M−3.2% Reduced
MMEDMinimed Group, Inc.1.11%$22.7m1.52M+44.1% Added
BSXBoston Scientific1.10%$22.6m528.5K+2.6% Added
PHVSPharvaris N.V.1.09%$22.4m648.3K+0.4%
AVLNAvalyn Pharma Inc.1.06%$21.8m662.9KNew
COAGHemab Therapeutics Holdings, Inc.1.03%$21.1m575.4KNew
DYNDyne Therapeutics, Inc.1.02%$20.9m942.2K−3.1% Reduced
ALNYAlnylam Pharmaceuticals, Inc.0.98%$20.1m66.8K−9.8% Reduced
COGTCogent Biosciences, Inc.0.97%$20.0m515.9K−17.3% Reduced
AGIOAgios Pharmaceuticals, Inc.0.96%$19.8m532.6K−33.4% Reduced
NAMSNewamsterdam Pharma Co N.V.0.96%$19.7m582.7K−1.0% Reduced
VERAVera Therapeutics, Inc.0.90%$18.3m427.6K−15.1% Reduced
TARSTarsus Pharmaceuticals, Inc.0.85%$17.4m277.1K+23.1% Added
HTFLHeartflow, Inc.0.82%$16.8m573.5K+0.2%
MBXMBX Biosciences, Inc.0.80%$16.5m298.2K+3.6% Added
CYTKCytokinetics Inc0.78%$16.0m188.0K+314.4% Added
BCAXBicara Therapeutics Inc.0.78%$15.9m535.3K+9.4% Added
PBLSParabilis Medicines, Inc.0.77%$15.8m578.0KNew
ZLABZai Lab Ltd0.76%$15.5m814.7K0.0%
DHRDanaher Corporation0.71%$14.5m76.3K+24.1% Added
TNGXTango Therapeutics, Inc.0.70%$14.3m456.6K+18.0% Added
EVHEvolent Health, Inc.0.66%$13.6m2.50M−6.5% Reduced
PTCTPTC Therapeutics, Inc.0.65%$13.2m162.3K+0.3%
MLYSMineralys Therapeutics, Inc.0.64%$13.1m485.0K+10.3% Added
ZBIOZenas Biopharma, Inc.0.62%$12.7m502.1K0.0%
ARDXArdelyx, Inc.0.56%$11.4m2.24M−2.5% Reduced
INSPInspire Medical Systems, Inc.0.53%$10.9m244.0K+85.1% Added
BBIOBridgebio Pharma, Inc.0.53%$10.8m144.8K+12.9% Added
ALKSAlkermes plc.0.51%$10.5m199.8K+8.6% Added
SMMTSummit Therapeutics Inc.0.51%$10.4m715.0K+0.7% Added
AZTAAzenta, Inc.0.50%$10.3m403.0K−29.2% Reduced
INDVIndivior Pharmaceuticals, Inc.0.49%$10.1m245.5K+22.8% Added
SYKStryker Corporation0.45%$9.1m29.0K+95.9% Added
AMLXAmylyx Pharmaceuticals, Inc.0.44%$9.0m499.8K0.0%
CAICaris Life Sciences, Inc.0.42%$8.7m487.5K−13.4% Reduced
OMDAOmada Health, Inc.0.40%$8.2m373.0K−31.1% Reduced
CMPXCompass Therapeutics, Inc.0.38%$7.7m3.52M+6.6% Added
IMNMImmunome Inc.0.36%$7.4m347.7K0.0%
FOCLEdap TMS SA0.35%$7.2m1.39M+0.6% Added
OMEROmeros Corp0.33%$6.8m718.5KNew
DFTXDefinium Therapeutics, Inc.0.33%$6.7m143.2KNew
CORTCorcept Therapeutics Inc0.31%$6.3m72.0K+43.3% Added
JANXJanux Therapeutics, Inc.0.28%$5.6m367.0K0.0%
MOBIMobia Medical, Inc.0.27%$5.6m418.2KNew
RCUSArcus Biosciences, Inc.0.27%$5.5m180.0K0.0%
TMOThermo Fisher Scientific0.24%$5.0m10.0K0.0%
TRVITrevi Therapeutics, Inc.0.24%$4.8m260.0KNew
SIONSionna Therapeutics, Inc.0.21%$4.4m99.4K0.0%
CVSCVS Health0.20%$4.1m40.0K0.0%
EYPTEyepoint, Inc.0.19%$3.8m268.5K+3.8% Added
OCULOcular Therapeutix, Inc0.18%$3.8m383.7K0.0%
SYRESpyre Therapeutics, Inc.0.18%$3.8m42.3KNew
TLPHTalphera, Inc.0.18%$3.7m3.59M0.0%
ROIVRoivant Sciences Ltd.0.17%$3.6m101.0K+4.1% Added
PCVXVaxcyte, Inc.0.17%$3.5m60.3K0.0%
NGNENeurogene Inc.0.16%$3.4m106.8K+2.3% Added
IPSCCentury Therapeutics, Inc.0.16%$3.2m1.30M0.0%
ATECAlphatec Holdings, Inc.0.15%$3.1m360.0K+2.9% Added
NVONovo Nordisk A S0.15%$3.0m63.5K−29.4% Reduced
OLMAOlema Pharmaceuticals, Inc.0.14%$2.9m235.2K+38.0% Added
NGENNervgen Pharma Corp.0.12%$2.5m1.21MNew
MDTMedtronic0.12%$2.4m30.9KNew
TEVATeva Pharmaceutical Industries LTD0.10%$2.0m59.0K+29.7% Added
DNTHDianthus Therapeutics, Inc.0.10%$2.0m20.3K−24.0% Reduced
SGMTSagimet Biosciences Inc.0.09%$1.9m250.0KNew
CAPRCapricor Therapeutics, Inc.0.09%$1.8m74.4KNew
LENZLenz Therapeutics, Inc.0.07%$1.5m257.5K0.0%
ALTAltimmune, Inc.0.07%$1.4m471.5KNew
KLRAKailera Therapeutics, Inc.0.07%$1.4m65.0KNew
SGRYSurgery Partners, Inc.0.07%$1.4m84.0K−59.6% Reduced
AXSMAxsome Therapeutics, Inc.0.07%$1.3m5.5KNew
ORKAOruka Therapeutics, Inc.0.06%$1.1m12.1K+192.3% Added
VKTXViking Therapeutics, Inc.0.05%$994,75525.5K−73.4% Reduced
LEGNLegend Biotech Corp0.05%$967,48033.5K−17.3% Reduced
GKOSGlaukos Corp0.03%$663,8604.8KNew
JSPRJasper Therapeutics, Inc.0.02%$463,4061.10M0.0%
BCRXBiocryst Pharmaceuticals Inc0.01%$221,24022.1K+75.6% Added
MLTXMoonlake Immunotherapeutics0.01%$208,25110.7K−82.7% Reduced
CompanyBought (value)Shares
ASNDAscendis Pharma A/s$45.0m168.8K
TVTXTravere Therapeutics, Inc.$39.8m701.1K
AVLNAvalyn Pharma Inc.$21.8m662.9K
COAGHemab Therapeutics Holdings, Inc.$21.1m575.4K
PBLSParabilis Medicines, Inc.$15.8m578.0K
CYTKCytokinetics Inc$12.1m142.6K
MMEDMinimed Group, Inc.$7.0m465.0K
OMEROmeros Corp$6.8m718.5K
DFTXDefinium Therapeutics, Inc.$6.7m143.2K
MOBIMobia Medical, Inc.$5.6m418.2K
ERASErasca, Inc.$5.5m298.7K
INSMInsmed Inc$5.1m47.9K
INSPInspire Medical Systems, Inc.$5.0m112.2K
TRVITrevi Therapeutics, Inc.$4.8m260.0K
SYKStryker Corporation$4.5m14.2K

Change in shares on the previous quarter's 13F, valued at this quarter's reported price.

CompanySold (value)Shares
ARGXArgenx SE−$42.4m−45.8K
RVMDRevolution Medicines, Inc.−$19.5m−104.3K
ELVNEnliven Therapeutics, Inc.−$18.4m−361.9K
AGIOAgios Pharmaceuticals, Inc.−$9.9m−266.6K
RAREUltragenyx Pharmaceutical Inc.−$8.4m−250.9K
REGNRegeneron Pharmaceuticals−$7.8m−10.1K
KYMRKymera Therapeutics, Inc.−$5.0m−43.7K
XENEXenon Pharmaceuticals Inc.−$4.8m−79.1K
AZTAAzenta, Inc.−$4.2m−166.1K
COGTCogent Biosciences, Inc.−$4.2m−108.2K
OMDAOmada Health, Inc.−$3.7m−168.0K
VERAVera Therapeutics, Inc.−$3.3m−76.0K
VKTXViking Therapeutics, Inc.−$2.8m−70.5K
EWEdwards Lifesciences−$2.3m−28.9K
ISRGIntuitive Surgical−$2.2m−5.5K

Change in shares on the previous quarter's 13F, valued at this quarter's reported price.

CompanyValue last quarterShares
REGNRegeneron Pharmaceuticals$7.8m10.1K
EWEdwards Lifesciences$2.3m28.9K
ACHCAcadia Healthcare Company, Inc.$1.8m75.5K
JAZZJazz Pharmaceuticals plc$1.1m5.8K
GOSSGossamer Bio, Inc.$528,7181.61M
  • Health Care100.0%

Share of the value held in companies we cover, by sector.

PeriodCopy, a yearS&P 500SharpeS&P 500Biggest dropBeta
Whole backtestFebruary 21, 2014 to November 2, 2026+6.4%+13.7%0.300.75−45.5%1.03
2018 onwardsJanuary 5, 2018 to November 2, 2026+5.0%+13.9%0.210.66−45.5%1.02
Last three yearsNovember 3, 2023 to November 2, 2026+12.5%+21.8%0.441.16−25.7%0.92
Last yearNovember 7, 2025 to November 2, 2026+11.1%+14.2%0.390.84−17.9%1.00

From SEC Form 13F data sets. A 13F lists long positions in US-listed shares at the quarter's end, filed up to 45 days later; it does not show shorts, cash, bonds, non-US holdings or trades within the quarter. Positions in companies outside our coverage are not listed here. Research, not investment advice.