Skip to main content
Livermore
Livermore
ZHEN

Rock Springs Capital Management LP

SEC CIK
0001595725
Latest filing
Aug 14, 2026

The latest 13F from Rock Springs Capital Management LP covers Q2 2026 (filed Aug 14, 2026): 104 long positions worth $2.05B. The top 10 holdings make up 44.0% of the portfolio, and the largest is Revolution Medicines, Inc. (RVMD) at 10.1%. Livermore has 22 filings on Form 13F from this institution, going back to Q1 2021.

What changed in Q2 2026

Share counts compared with Q1 2026: how many positions were new, added to, reduced or sold out, and the biggest buys and sells. Dollar amounts are estimated at the quarter-end prices implied by the filing.

Full comparison
New
16
Est. +$100.1M
Added
40
Est. +$111.1M
Reduced
31
Est. −$153.2M
Sold out
12
Est. −$72.3M

Top 5 holdings

Share of this quarter's portfolio value

  1. RVMDRevolution Medicines, Inc.
    10.1%$207.0MHistory
  2. TVTXTravere Therapeutics, Inc.
    6.0%$123.8MHistory
  3. LLYEli Lilly & Co
    5.8%$118.4MHistory
  4. MDGLMadrigal Pharmaceuticals, Inc.
    4.6%$94.0MHistory
  5. MIRMMirum Pharmaceuticals, Inc.
    4.6%$93.4MHistory

Share of portfolio

Top 5 holdings and the other 99 positions, by share of portfolio value

  1. RVMD10.1%
  2. TVTX6.0%
  3. LLY5.8%
  4. MDGL4.6%
  5. MIRM4.6%
  6. Other 99 positions68.9%

Biggest buys

New and added positions, by estimated amount bought

  1. TVTXTravere Therapeutics, Inc.
    +$39.8MAddedHistory
  2. AVLNAvalyn Pharma Inc.
    +$21.8MNewHistory
  3. COAGHemab Therapeutics Holdings, Inc.
    +$21.1MNewHistory
  4. PBLSParabilis Medicines, Inc.
    +$15.8MNewHistory
  5. CYTKCytokinetics Inc
    +$12.1MAddedHistory

Largest weight increases

New and added positions, by percentage points of the portfolio gained

  1. TVTXTravere Therapeutics, Inc.
    +3.45 pp2.6% → 6.0%History
  2. AGLagilon health, inc.
    +1.25 pp0.1% → 1.4%History
  3. AVLNAvalyn Pharma Inc.
    +1.07 pp0.0% → 1.1%History
  4. COAGHemab Therapeutics Holdings, Inc.
    +1.03 pp0.0% → 1.0%History
  5. PBLSParabilis Medicines, Inc.
    +0.77 pp0.0% → 0.8%History

Biggest sells

Reduced and sold-out positions, by estimated amount sold

  1. ARGXArgenx SE
    −$42.4MReducedHistory
  2. RVMDRevolution Medicines, Inc.
    −$19.5MReducedHistory
  3. ACLXArcellx, Inc.
    −$19.5MSold outHistory
  4. ELVNEnliven Therapeutics, Inc.
    −$18.4MReducedHistory
  5. CNTACentessa Pharmaceuticals plc
    −$14.0MSold outHistory

Largest weight decreases

Reduced and sold-out positions, by percentage points of the portfolio lost

  1. ARGXArgenx SE
    −1.85 pp4.2% → 2.4%History
  2. ACLXArcellx, Inc.
    −1.15 pp1.1% → 0.0%History
  3. CNTACentessa Pharmaceuticals plc
    −0.82 pp0.8% → 0.0%History
  4. ELVNEnliven Therapeutics, Inc.
    −0.76 pp1.9% → 1.2%History
  5. ISRGIntuitive Surgical Inc
    −0.74 pp2.2% → 1.5%History

Metrics

13F metrics for Q2 2026, computed only from the numbers in the filings. Definitions below.

Portfolio value
$2.05B
+$352.2M (+20.8%) vs. prior quarter
Positions
104
+4 vs. prior quarter
Top 10 concentration
44.0%
Top 10 as share of value
Turnover
11.3%
Q2 2026, one quarter
Average holding period
13.5 quarters
Weighted by value

How these are calculated

  • Portfolio value: the market value of all long positions in the 13F, as reported at quarter end, excluding options.
  • Top 10 concentration: the combined value of the 10 largest positions as a share of portfolio value.
  • Turnover: the smaller of this quarter's estimated purchases and estimated sales, divided by the average of this and last quarter's portfolio value. Estimates multiply the change in shares by the quarter-end price implied by the filing (market value divided by shares); new positions use this quarter's value and sold-out positions last quarter's. Only positions reported in shares count, and it is not calculated when the previous quarter was not filed.
  • Average holding period: how many consecutive quarters each current position has been held (including this one; a quarter without the position or without a filing starts the count over), weighted by this quarter's value. Counting starts with the first 13F in Livermore (Q1 2021), so positions held before then are understated.

13F filings by quarter

22 quarters, going back to Q1 2021. Bars show each quarter's 13F portfolio value; quarters without a filing are left blank.

Peak $5.05B (Q2 2021)

Q1 2021: $4.58BQ2 2021: $5.05BQ3 2021: $4.76BQ4 2021: $4.33BQ1 2022: $3.97BQ2 2022: $3.44BQ3 2022: $3.87BQ4 2022: $4.16BQ1 2023: $4.19BQ2 2023: $4.20BQ3 2023: $3.73BQ4 2023: $4.05BQ1 2024: $3.93BQ2 2024: $3.31BQ3 2024: $3.07BQ4 2024: $2.63BQ1 2025: $1.75BQ2 2025: $1.60BQ3 2025: $1.71BQ4 2025: $1.95BQ1 2026: $1.70BQ2 2026: $2.05B
Q1 2021Q2 2026
13F filings of Rock Springs Capital Management LP by quarter
QuarterFiledPositionsValueTop 3 holdingsChangesFiling
Q2 2026Aug 14, 2026104$2.05BRVMDTVTXLLYvs. Q1 2026SEC
Q1 2026May 15, 2026100$1.70BRVMDLLYMDGLvs. Q4 2025SEC
Q4 2025Feb 17, 202698$1.95BLLYRVMDARGXvs. Q3 2025SEC
Q3 2025Nov 14, 202592$1.71BARGXLLYRYTMvs. Q2 2025SEC
Q2 2025Aug 14, 202593$1.60BARGXLLYMRUSvs. Q1 2025SEC
Q1 2025May 15, 202596$1.75BARGXLLYBPMCvs. Q4 2024SEC
Q4 2024Feb 14, 2025107$2.63BARGXISRGLLYvs. Q3 2024SEC
Q3 2024Nov 14, 2024109$3.07BUNHISRGARGXvs. Q2 2024SEC
Q2 2024Aug 14, 2024110$3.31BBPMCUNHISRGvs. Q1 2024SEC
Q1 2024May 15, 2024113$3.93BBPMCIMCRNBIXvs. Q4 2023SEC
Q4 2023Feb 14, 2024103$4.05BBPMCIMCRKRTXvs. Q3 2023SEC
Q3 2023Nov 14, 2023120$3.73BHUMIMCRAGLvs. Q2 2023SEC
Q2 2023Aug 14, 2023123$4.20BHUMIMCRPODDvs. Q1 2023SEC
Q1 2023May 15, 2023120$4.19BHUMAGLPODDvs. Q4 2022SEC
Q4 2022Feb 14, 2023120$4.16BHUMIMCRPODDvs. Q3 2022SEC
Q3 2022Nov 14, 2022127$3.87BHUMAGLIMCRvs. Q2 2022SEC
Q2 2022Aug 15, 2022131$3.44BHUMAGLUNHvs. Q1 2022SEC
Q1 2022May 16, 2022135$3.97BAGLHUMPODDvs. Q4 2021SEC
Q4 2021Feb 14, 2022136$4.33BAGLHUMALGNvs. Q3 2021SEC
Q3 2021Nov 15, 2021153$4.76BAGLHUMALGNvs. Q2 2021SEC
Q2 2021Aug 16, 2021155$5.05BAGLZLABAGIOvs. Q1 2021SEC
Q1 2021May 17, 2021151$4.58BAGIOHUMZLAB–SEC

13D and 13G filings

Companies where Rock Springs Capital Management LP reports owning 5% or more on Schedule 13D or 13G, and its latest filings.

Current stakes of 5% or more

1 company, largest stake first.

Companies where Rock Springs Capital Management LP owns 5% or more
CompanyLatest formStakeChangeFirst filedLatest filingFiling
TLPHTalphera, Inc.13G7.88%3.59M sharesNewSep 12, 20251 filingSep 12, 2025SEC

Latest filings

66 filings on file made by Rock Springs Capital Management LP or listing it as a reporting person; the latest 20 are shown.

Schedule 13D and 13G filings by Rock Springs Capital Management LP
CompanyFiled (ET)FormStakeChangeEvent dateFiling
TLPHTalphera, Inc.Sep 12, 20254:38 PM ET13G7.88%3.59M sharesNewSep 10, 2025SEC
INZYInozyme Pharma, Inc.Aug 13, 20254:31 PM ET13G/A0.00%0 shares–Below 5%Jun 30, 2025SEC
SPRBSpruce Biosciences, Inc.Aug 13, 20254:31 PM ET13G/A0.00%0 shares–Below 5%Jul 3, 2025SEC
XLOXilio Therapeutics, Inc.May 15, 202510:48 AM ET13G/A0.00%0 shares–Below 5%Mar 31, 2025SEC
TVTXTravere Therapeutics, Inc.May 15, 202510:47 AM ET13G/A3.30%2.92M shares−2.42 ppfrom 5.72%Below 5%Mar 31, 2025SEC
MREOMereo BioPharma Group plcMay 15, 202510:46 AM ET13G/A4.20%33.4M shares–Below 5%Mar 31, 2025SEC
ACRSAclaris Therapeutics, Inc.May 15, 202510:45 AM ET13G/A4.70%5.05M shares–Below 5%Mar 31, 2025SEC
TVTXTravere Therapeutics, Inc.Feb 14, 20259:10 AM ET13G/A5.72%4.97M shares–Dec 31, 2024SEC
ACRSAclaris Therapeutics, Inc.Nov 22, 202413GOld format–––SEC
XLOXilio Therapeutics, Inc.Nov 12, 202413G/AOld format–––SEC
MREOMereo BioPharma Group plcNov 12, 202413G/AOld format–––SEC
IMCRImmunocore Holdings plcNov 12, 202413G/AOld format–––SEC
TVTXTravere Therapeutics, Inc.May 1, 202413GOld format–New–SEC
XLOXilio Therapeutics, Inc.Apr 5, 202413G/AOld format–––SEC
XLOXilio Therapeutics, Inc.Feb 14, 202413GOld format–New–SEC
TPSTTempest Therapeutics, Inc.Feb 14, 202413G/AOld format–––SEC
SPRBSpruce Biosciences, Inc.Feb 14, 202413G/AOld format–––SEC
MREOMereo BioPharma Group plcFeb 14, 202413G/AOld format–––SEC
MREOMereo BioPharma Group plcFeb 14, 202413G/AOld format–––SEC
INZYInozyme Pharma, Inc.Feb 14, 202413G/AOld format–––SEC