SEC 13F Intelligence

Managers / Q4 2023 · view latest →

Rock Springs Capital Management LP

CIK 0001595725 · 650 SOUTH EXETER STREET, SUITE 1070, BALTIMORE, MD, 21202 · 4102200129

Reported Value
$4.1B
Q4 2023
Positions
104
Filings on Record
30
2019–present window
Filed
Feb 14, 2024
original filing

Summary

Rock Springs Capital Management LP reported $4.1B in U.S.-listed holdings across 104 positions for Q4 2023.

Its largest position, 2655787D, represents 6.5% of the portfolio.

Compared with Q3 2023, the fund opened 4 new positions and exited 20.

Portfolio Metrics

Turnover
+14.6%
vs prior filed quarter
Top-10 Concentration
+37.4%
share of reported value
Largest Position
+6.5%
Blueprint Medicines
New / Exited
4 / 20
positions this quarter

Methodology: turnover is min(value bought, value sold) ÷ average reported value across the two quarters — value-based, so market moves inflate it slightly versus a share-based measure. Concentration and largest position are shares of the filing’s total reported value, options excluded. New/exited counts compare against the prior filed quarter. All figures derive solely from the fund’s 13F filings.

Reported Value by Quarter

13F Reported Value
Q4 ’18: $2.1BQ4 ’18Q1 ’19: $2.6BQ2 ’19: $2.8BQ3 ’19: $2.5BQ4 ’19: $3.2BQ4 ’19Q1 ’20: $2.4BQ2 ’20: $3.6BQ3 ’20: $3.9BQ4 ’20: $4.7BQ4 ’20Q1 ’21: $4.6BQ2 ’21: $5.1BQ3 ’21: $4.8BQ4 ’21: $4.3BQ4 ’21Q1 ’22: $4.0BQ2 ’22: $3.4BQ3 ’22: $3.9BQ4 ’22: $4.2BQ4 ’22Q1 ’23: $4.2BQ2 ’23: $4.2BQ3 ’23: $3.7BQ4 ’23: $4.1BQ4 ’23Q1 ’24: $3.9BQ2 ’24: $3.3BQ3 ’24: $3.1BQ4 ’24: $2.6BQ4 ’24Q1 ’25: $1.7BQ2 ’25: $1.6BQ3 ’25: $1.7BQ4 ’25: $2.0BQ4 ’25Q1 ’26: $1.7Bfilingsflow.com

Portfolio Composition

By security type
Common Stock: 79.2%Other: 11.5%ADR: 9.1%US DOMESTIC: 0.2%Equity WRT: 0.0%
  • Common Stock · 79.2% · $3.2B
  • Other · 11.5% · $466M
  • ADR · 9.1% · $369M
  • US DOMESTIC · 0.2% · $8M
  • Equity WRT · 0.0% · $8,042

Quarter-over-Quarter Changes full breakdown →

vs Q3 2023 (amended baseline)

IssuerMoveShare ΔShares nowValue ΔValue now
LLYELI LILLY & CONEW+69.5K69.5K+$41M$41M
GPCRSTRUCTURE THERAPEUTICS INCNEW+286.7K286.7K+$12M$12M
INBXUSDINHIBRX INCNEW+301.4K301.4K+$11M$11M
OSCROSCAR HEALTH INCNEW+735.0K735.0K+$7M$7M
INSPINSPIRE MED SYS INCADDED+54.5K99.0K+$11M$20M
SGENUSDSEAGEN INCSOLD OUT−400.2K0−$85M$0
HORIZON THERAPEUTICS PUB LSOLD OUT−255.5K0−$30M$0
ABCAM PLCSOLD OUT−1.27M0−$29M$0

Value changes conflate price moves with buying and selling — share changes are the real signal. Share counts are not split-adjusted.

Holdings — Q4 2023

50 positions
Export to Excel
#IssuerClass% PortfolioValue ↓Shares
12655787DBLUEPRINT MEDICINES CORPhistory →COM6.54%$266M2.88M
2IMCRIMMUNOCORE HLDGS PLChistory →ADS4.48%$182M2.66M
3KARUNA THERAPEUTICS INCCOM4.01%$163M515.0K
4NBIXNEUROCRINE BIOSCIENCES INChistory →COM3.88%$158M1.20M
5HUMHUMANA INChistory →COM3.49%$142M310.0K
6PENPENUMBRA INChistory →COM3.33%$135M537.5K
7EVHEVOLENT HEALTH INChistory →CL A3.22%$131M3.96M
8UNHUNITEDHEALTH GROUP INChistory →COM2.98%$121M230.0K
9CEREVEL THERAPEUTICS HLDNG ICOM2.79%$113M2.67M
10AGILON HEALTH INCCOM2.67%$108M8.63M
11ISRGINTUITIVE SURGICAL INChistory →COM NEW2.48%$101M298.5K
12IDXXIDEXX LABS INChistory →COM2.45%$99M179.3K
13PODDINSULET CORPhistory →COM2.31%$94M431.8K
14ARGXARGENX SEhistory →SPONSORED ADR2.15%$87M229.3K
15RAREULTRAGENYX PHARMACEUTICAL INhistory →COM2.06%$84M1.75M
16ACHCACADIA HEALTHCARE COMPANY INhistory →COM2.05%$83M1.07M
17EXKEXACT SCIENCES CORPhistory →COM1.86%$75M1.02M
18DC4DEXCOM INChistory →COM1.82%$74M596.0K
19BSXBOSTON SCIENTIFIC CORPhistory →COM1.75%$71M1.23M
20RYTMRHYTHM PHARMACEUTICALS INChistory →COM1.72%$70M1.52M
21AFWALIGN TECHNOLOGY INChistory →COM1.48%$60M220.0K
22XENEXENON PHARMACEUTICALS INChistory →COM1.42%$58M1.26M
23FRPTFRESHPET INChistory →COM1.41%$57M662.5K
24MIRMMIRUM PHARMACEUTICALS INChistory →COM1.35%$55M1.85M
25PHRPHREESIA INChistory →COM1.26%$51M2.21M
26EWEDWARDS LIFESCIENCES CORPhistory →COM1.22%$49M647.3K
27MRTXEURMIRATI THERAPEUTICS INChistory →COM1.21%$49M835.8K
28WSTWEST PHARMACEUTICAL SVSC INChistory →COM1.19%$48M137.3K
29AGIOAGIOS PHARMACEUTICALS INChistory →COM1.18%$48M2.15M
30MDGLMADRIGAL PHARMACEUTICALS INChistory →COM1.13%$46M198.2K
31ALNYALNYLAM PHARMACEUTICALS INChistory →COM1.11%$45M235.0K
32OLINK HLDG ABSPONSORED ADS1.04%$42M1.68M
33ACCDUSDACCOLADE INChistory →COM1.03%$42M3.48M
34IMVTIMMUNOVANT INChistory →COM1.02%$41M983.3K
35LLYELI LILLY & COhistory →COM1.00%$41M69.5K
36KYMRKYMERA THERAPEUTICS INChistory →COM0.95%$39M1.52M
37TCE2CELLDEX THERAPEUTICS INC NEWhistory →COM NEW0.95%$38M969.6K
38IRTCIRHYTHM TECHNOLOGIES INChistory →COM0.92%$38M350.8K
39ASCENDIS PHARMA A/SSPONSORED ADR0.90%$37M290.0K
40PCRXPACIRA BIOSCIENCES INChistory →COM0.88%$36M1.06M
41LFSTLIFESTANCE HEALTH GROUP INChistory →COM0.87%$36M4.54M
42AZTAAZENTA INChistory →COM0.81%$33M507.5K
43SRPTSAREPTA THERAPEUTICS INChistory →COM0.78%$32M327.6K
44ZLABZAI LAB LTDhistory →ADR0.76%$31M1.14M
45LEGNLEGEND BIOTECH CORPhistory →SPONSORED ADS0.73%$30M492.4K
46WRBYWARBY PARKER INChistory →CL A COM0.70%$29M2.03M
47AKROAKERO THERAPEUTICS INChistory →COM0.62%$25M1.08M
48TVTXTRAVERE THERAPEUTICS INChistory →COM0.61%$25M2.77M
49MERUS N VCOM0.59%$24M872.1K
50DVAXDYNAVAX TECHNOLOGIES CORPhistory →COM NEW0.58%$23M1.68M

Filing History

QuarterReported ValuePositionsFiledTypeLinks
Q1 2026$1.7B100May 15, 202613F-HRchanges · EDGAR ↗
Q4 2025$2.0B99Feb 17, 202613F-HRchanges · EDGAR ↗
Q3 2025$1.7B93Nov 14, 202513F-HRchanges · EDGAR ↗
Q2 2025$1.6B93Aug 14, 202513F-HRchanges · EDGAR ↗
Q1 2025$1.7B96May 15, 202513F-HRchanges · EDGAR ↗
Q4 2024$2.6B107Feb 14, 202513F-HRchanges · EDGAR ↗
Q3 2024$3.1B109Nov 14, 202413F-HRchanges · EDGAR ↗
Q2 2024$3.3B112Aug 14, 202413F-HRchanges · EDGAR ↗
Q1 2024$3.9B114May 15, 202413F-HRchanges · EDGAR ↗
Q4 2023$4.1B104Feb 14, 202413F-HRchanges · EDGAR ↗
Q3 2023$3.7B120Nov 14, 202313F-HRchanges · EDGAR ↗
Q2 2023$4.2B123Aug 14, 202313F-HRchanges · EDGAR ↗
Q1 2023$4.2B121May 15, 202313F-HRchanges · EDGAR ↗
Q4 2022$4.2B120Feb 14, 202313F-HRchanges · EDGAR ↗
Q3 2022$3.9B128Nov 14, 202213F-HRchanges · EDGAR ↗
Q2 2022$3.4B131Aug 15, 202213F-HRchanges · EDGAR ↗
Q1 2022$4.0B135May 16, 202213F-HRchanges · EDGAR ↗
Q4 2021$4.3B136Feb 14, 202213F-HRchanges · EDGAR ↗
Q3 2021$4.8B153Nov 15, 202113F-HRchanges · EDGAR ↗
Q2 2021$5.1B156Aug 16, 202113F-HRchanges · EDGAR ↗
Q1 2021$4.6B151May 17, 202113F-HRchanges · EDGAR ↗
Q4 2020$4.7B155Feb 16, 202113F-HRchanges · EDGAR ↗
Q3 2020$3.9B148Nov 16, 202013F-HRchanges · EDGAR ↗
Q2 2020$3.6B143Aug 14, 202013F-HRchanges · EDGAR ↗
Q1 2020$2.4B131May 15, 202013F-HRchanges · EDGAR ↗
Q4 2019$3.2B130Feb 14, 202013F-HRchanges · EDGAR ↗
Q3 2019$2.5B138Nov 14, 201913F-HRchanges · EDGAR ↗
Q2 2019$2.8B135Aug 14, 201913F-HRchanges · EDGAR ↗
Q1 2019$2.6B131May 15, 201913F-HRchanges · EDGAR ↗
Q4 2018$2.1B133Feb 14, 201913F-HRchanges · EDGAR ↗

13F filings are due up to 45 days after quarter end, so holdings shown here lag the fund’s current book. Source: original SEC filing on EDGAR ↗.