Latest Rock Springs Capital Management LP Stock Portfolio

Rock Springs Capital Management LP Performance:

2025 Q4: 17.96%YTD: 36.21%2024: -4.87%

Performance for 2025 Q4 is 17.96%, and YTD is 36.21%, and 2024 is -4.87%.

About Rock Springs Capital Management LP and 13F Hedge Fund Stock Holdings

Rock Springs Capital Management LP is a hedge fund based in Baltimore, MD. On 2026-02-17, the fund reported it's updated stock portfolio. In the 13F Holdings report, Rock Springs Capital Management LP reported an equity portfolio of $2 Billions as of 31 Dec, 2025.

The top stock holdings of Rock Springs Capital Management LP are LLY, RVMD, ARGX. The fund has invested 5.8% of it's portfolio in ELI LILLY & CO and 5.4% of portfolio in REVOLUTION MEDICINES INC.

The fund managers got completely rid off MERUS N V (MRUS), AKERO THERAPEUTICS INC (AKRO) and MEREO BIOPHARMA GROUP PLC (MREO) stocks. They significantly reduced their stock positions in ACADIA HEALTHCARE COMPANY IN (ACHC), ARGENX SE (ARGX) and STRUCTURE THERAPEUTICS INC. Rock Springs Capital Management LP opened new stock positions in UNITEDHEALTH GROUP INC (UNH), IMMUNOME INC (IMNM) and RAPT THERAPEUTICS INC (RAPT). The fund showed a lot of confidence in some stocks as they added substantially to EYEPOINT INC (EYPT), CENTESSA PHARMACEUTICALS PLC (CNTA) and VAXCYTE INC (PCVX).

Rock Springs Capital Management LP Annual Return Estimates Vs S&P 500

Our best estimate is that Rock Springs Capital Management LP made a return of 17.96% in the last quarter. In trailing 12 months, it's portfolio return was 36.21%.

Performance
S&P 500

New Buys

Ticker	$ Bought
unitedhealth group inc	13,468,500
immunome inc	7,467,870
rapt therapeutics inc	7,239,070
surgery partners inc	4,789,500
ptc therapeutics inc	4,700,330
terns pharmaceuticals inc	4,382,630
arcus biosciences inc	4,289,400
theravance biopharma inc	3,906,100

New stocks bought by Rock Springs Capital Management LP

Additions

Ticker	% Inc.
eyepoint inc	717
centessa pharmaceuticals plc	367
vaxcyte inc	323
moonlake immunotherapeutics	118
janux therapeutics inc	70.56
apellis pharmaceuticals inc	63.59
soleno therapeutics inc	59.88
spdr series trust	46.29

Additions to existing portfolio by Rock Springs Capital Management LP

Reductions

Ticker	% Reduced
acadia healthcare company in	-29.41
argenx se	-27.67
structure therapeutics inc	-21.33
omada health inc	-19.56
cidara therapeutics inc	-17.85
insmed inc	-17.08
agios pharmaceuticals inc	-16.63
cogent biosciences inc	-15.8

Rock Springs Capital Management LP reduced stake in above stock

Sold off

Ticker	$ Sold
mereo biopharma group plc	-9,415,540
applied therapeutics inc	-1,255,770
akero therapeutics inc	-29,747,500
merus n v	-56,212,400
perspective therapeutics inc	-1,524,230
immunovant inc	-1,176,200
novavax inc	-390,150
korro bio inc	-1,710,580

Rock Springs Capital Management LP got rid off the above stocks

Sector Distribution

Rock Springs Capital Management LP has about 81.2% of it's holdings in Healthcare sector.

Sector	%
Healthcare	81.2
Others	18.8

Market Cap. Distribution

Rock Springs Capital Management LP has about 37% of it's portfolio invested in the large-cap and mega-cap stocks.

Category	%
MID-CAP	31.2
LARGE-CAP	30.5
UNALLOCATED	18.8
SMALL-CAP	12.1
MEGA-CAP	6.5

Stocks belong to which Index?

About 61.4% of the stocks held by Rock Springs Capital Management LP either belong to S&P 500 or RUSSELL 2000 index.

Index	%
RUSSELL 2000	47.6
Others	38.5
S&P 500	13.8

Top 5 Winners (%)		%
MRSN	mersana therapeutics inc	272.8 %
COGT	cogent biosciences inc	135.7 %
	structure therapeutics inc	132.6 %
CDTX	cidara therapeutics inc	119.0 %
EXAS	exact sciences corp	84.5 %

Top 5 Winners ($)		$
RVMD	revolution medicines inc	44.0 M
	structure therapeutics inc	35.3 M
LLY	eli lilly & co	32.9 M
TVTX	travere therapeutics inc	31.3 M
CDTX	cidara therapeutics inc	28.4 M

Top 5 Losers (%)		%
	lenz therapeutics inc	-64.7 %
EVH	evolent health inc	-50.3 %
ZLAB	zai lab ltd	-47.6 %
JANX	janux therapeutics inc	-38.0 %
ACHC	acadia healthcare company in	-36.4 %

Top 5 Losers ($)		$
ZLAB	zai lab ltd	-13.0 M
EVH	evolent health inc	-12.5 M
AGIO	agios pharmaceuticals inc	-11.4 M
RARE	ultragenyx pharmaceutical in	-8.9 M
	lenz therapeutics inc	-7.5 M

Rock Springs Capital Management LP Holdings Map

This heatmap illustrates the top 50 positions within the fund's portfolio.

Current Stock Holdings of Rock Springs Capital Management LP

Rock Springs Capital Management LP has 97 stocks in it's portfolio. About 39.8% of the portfolio is in top 10 stocks. ZLAB proved to be the most loss making stock for the portfolio. RVMD was the most profitable stock for Rock Springs Capital Management LP last quarter.

Last Reported on: 17 Feb, 2026

Ticker	Namesorted ascending	% Portfolio	Shares Held	$ Value	Type	% Change
ACHC	acadia healthcare company in	0.09	120,000	1,702,800	reduced	-29.41

ACLX	arcellx inc	0.57	169,859	11,074,800	reduced	-5.1

ACRS	aclaris therapeutics inc	0.69	4,453,740	13,405,800	reduced	-3.38

ACRX	talphera inc	0.21	3,589,190	4,091,670	unchanged	0.00

AGIO	agios pharmaceuticals inc	1.11	799,163	21,753,200	reduced	-16.63

AGL	agilon health inc	0.23	6,500,000	4,476,550	reduced	-6.69

AKRO	akero therapeutics inc	0.00	0.00	0.00	sold off	-100

ALKS	alkermes plc	0.20	139,228	3,895,600	added	30.69

ALNY	alnylam pharmaceuticals inc	1.45	71,250	28,332,600	reduced	-4.04

AMLX	amylyx pharmaceuticals inc	0.31	499,764	6,037,150	unchanged	0.00

APLS	apellis pharmaceuticals inc	0.19	150,500	3,780,560	added	63.59

APLT	applied therapeutics inc	0.00	0.00	0.00	sold off	-100

ARDX	ardelyx inc	0.69	2,299,470	13,405,900	added	0.58

ARGX	argenx se	4.45	103,250	86,828,100	reduced	-27.67

ASND	ascendis pharma a/s	2.22	203,500	43,394,300	reduced	-5.13

ATEC	alphatec hldgs inc	0.33	302,500	6,364,600	unchanged	0.00

AZTA	azenta inc	0.97	569,100	18,928,300	added	5.31

BBIO	bridgebio pharma inc	0.41	103,500	7,916,720	added	21.76

BIL	spdr series trust	1.39	222,000	27,068,500	added	46.29

BSX	boston scientific corp	1.95	399,050	38,049,400	added	10.77