Rock Springs Capital Management LP

13F filer, CIK 1595725, Baltimore, MD

Rock Springs Capital Management LP reported $3,073,721,559 across 109 holdings for the quarter ended 2024-09-30, in a 13F-HR filed 2024-11-14. Its ten largest share positions make up 34.44% of the portfolio.

Filed 2024-11-14 (acceptance time not in the bulk data set), ingested 2026-10-07 18:26:56 UTC13F-HR 0001172661-24-004721

Period: 2024-09-30
Reported value: $3.07B
Holdings: 109
Top 10 weight: 34.44%
New: 6
Sold out: 9

Largest buys vs the previous quarter

Security	Shares change	Approx. value
SMMTnew	+1,040,000	$22.8M
LLYadded	+20,500	$18.2M
NUVLadded	+174,005	$17.8M
ZBIOnew	+878,667	$14.9M
BCAXnew	+445,975	$11.4M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Largest sells vs the previous quarter

Security	Shares change	Approx. value
BLUEPRINT MEDICINES CORPreduced	-1,691,641	-$156M
IDXXexited	-119,500	-$58.2M
EVHreduced	-2,007,500	-$56.8M
BSXreduced	-357,500	-$30M
ACHCreduced	-362,500	-$23M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Holdings, Q3 2024

Share positions as resolved from 13F-HR 0001172661-24-004721, largest first. % of portfolio is the value over $3,073,721,559, the sum of the share positions whose value is usable for ratios (method).

Security	Shares	Value	% of portfolio	Change	Timeline
UNHUNITEDHEALTH GROUP INC	294,250	$172M	5.6%	+19,250	Timeline
ISRGINTUITIVE SURGICAL INC	270,000	$133M	4.32%	-28,500	Timeline
ARGXARGENX SE	233,500	$127M	4.12%	+4,250	Timeline
LLYELI LILLY & CO	142,000	$126M	4.09%	+20,500	Timeline
RAREULTRAGENYX PHARMACEUTICAL IN	1,978,272	$110M	3.58%	+54,200	Timeline
NBIXNEUROCRINE BIOSCIENCES INC	939,000	$108M	3.52%	-1,000	Timeline
EXASEXACT SCIENCES CORP	1,147,500	$78.2M	2.54%	+66,000	Timeline
BLUEPRINT MEDICINES CORPBLUEPRINT MEDICINES CORP	768,776	$71.1M	2.31%	-1,691,641
ALNYALNYLAM PHARMACEUTICALS INC	250,000	$68.8M	2.24%	0	Timeline
TVTXTRAVERE THERAPEUTICS INC	4,684,476	$65.5M	2.13%	+202,211	Timeline
RYTMRHYTHM PHARMACEUTICALS INC	1,228,093	$64.3M	2.09%	-52,400	Timeline
MIRMMIRUM PHARMACEUTICALS INC	1,580,488	$61.6M	2.01%	-191,550	Timeline
FRPTFRESHPET INC	446,500	$61.1M	1.99%	-33,500	Timeline
EVHEVOLENT HEALTH INC	2,070,000	$58.5M	1.9%	-2,007,500	Timeline
MDGLMADRIGAL PHARMACEUTICALS INC	263,062	$55.8M	1.82%	+17,563	Timeline
PHRPHREESIA INC	2,282,500	$52M	1.69%	-135,000	Timeline
XENEXENON PHARMACEUTICALS INC	1,316,477	$51.8M	1.69%	+43,600	Timeline
ACHCACADIA HEALTHCARE COMPANY IN	815,000	$51.7M	1.68%	-362,500	Timeline
PENPENUMBRA INC	265,000	$51.5M	1.68%	0	Timeline
WSTWEST PHARMACEUTICAL SVSC INC	167,750	$50.4M	1.64%	+22,250	Timeline
INSMINSMED INC	683,344	$49.9M	1.62%	-125,012	Timeline
KYMRKYMERA THERAPEUTICS INC	1,049,386	$49.7M	1.62%	-114,587	Timeline
ASNDASCENDIS PHARMA A/S	325,000	$48.5M	1.58%	+35,000	Timeline
HUMHUMANA INC	148,000	$46.9M	1.53%	+592	Timeline
GPCRSTRUCTURE THERAPEUTICS INC	1,063,910	$46.7M	1.52%	+64,048	Timeline
RVMDREVOLUTION MEDICINES INC	1,009,945	$45.8M	1.49%	+66,750	Timeline
MERUS N VMERUS N V	892,549	$44.6M	1.45%	-108,524
NUVLNUVALENT INC	429,994	$44M	1.43%	+174,005	Timeline
MREOMEREO BIOPHARMA GROUP PLC	9,534,170	$39.2M	1.27%	+250,678	Timeline
BSXBOSTON SCIENTIFIC CORP	460,000	$38.5M	1.25%	-357,500	Timeline
SRPTSAREPTA THERAPEUTICS INC	307,500	$38.4M	1.25%	+23,500	Timeline
EWEDWARDS LIFESCIENCES CORP	576,900	$38.1M	1.24%	+26,900	Timeline
CLDXCELLDEX THERAPEUTICS INC NEW	1,103,778	$37.5M	1.22%	-295,216	Timeline
AGLAGILON HEALTH INC COM (DE)	9,096,800	$35.8M	1.16%	+196,800	Timeline
DXCMDEXCOM INC	524,000	$35.1M	1.14%	+24,000	Timeline
IMVTIMMUNOVANT INC	1,221,309	$34.8M	1.13%	+35,655	Timeline
ZLABZAI LAB LTD	1,315,673	$31.8M	1.03%	+17,800	Timeline
PODDINSULET CORP	134,000	$31.2M	1.01%	-61,000	Timeline
AGIOAGIOS PHARMACEUTICALS INC	699,389	$31.1M	1.01%	-344,872	Timeline
IRTCIRHYTHM HOLDINGS INC	397,500	$29.5M	0.96%	0	Timeline
ALGNALIGN TECHNOLOGY INC	114,500	$29.1M	0.95%	-13,000	Timeline
BCRXBIOCRYST PHARMACEUTICALS INC	3,622,358	$27.5M	0.9%	+3,100	Timeline
INSPINSPIRE MED SYS INC	130,000	$27.4M	0.89%	0	Timeline
AKROAKERO THERAPEUTICS INC	933,399	$26.8M	0.87%	-140,862	Timeline
AZTAAZENTA INC	532,500	$25.8M	0.84%	-163,500	Timeline
LEGNLEGEND BIOTECH CORP	508,932	$24.8M	0.81%	+3,146	Timeline
WRBYWARBY PARKER INC	1,439,050	$23.5M	0.76%	-640,950	Timeline
SMMTSUMMIT THERAPEUTICS INC	1,040,000	$22.8M	0.74%	new	Timeline
LFSTLIFESTANCE HEALTH GROUP INC	3,101,000	$21.7M	0.71%	-1,726,700	Timeline
OSCROSCAR HEALTH INC	1,011,400	$21.5M	0.7%	-240,100	Timeline
INOZYME PHARMA INCINOZYME PHARMA INC	3,802,883	$19.9M	0.65%	+104,509
VERAVERA THERAPEUTICS INC	383,492	$17M	0.55%	+2,300	Timeline
DYNDYNE THERAPEUTICS INC	461,028	$16.6M	0.54%	0	Timeline
NVONOVO-NORDISK A S	132,000	$15.7M	0.51%	-15,500	Timeline
ZBIOZENAS BIOPHARMA INC	878,667	$14.9M	0.48%	new	Timeline
Applied Therapeutics IncApplied Therapeutics Inc	1,746,449	$14.8M	0.48%	+191,445
CRNXCRINETICS PHARMACEUTICALS IN	289,400	$14.8M	0.48%	0	Timeline
PHVSPHARVARIS N V	756,931	$14M	0.46%	0	Timeline
FOLDAMICUS THERAPEUTIC	1,250,280	$13.4M	0.43%	+31,700	Timeline
JNJJOHNSON & JOHNSON	80,000	$13M	0.42%	-90,000	Timeline
CGEMCULLINAN THERAPEUTICS INC	736,914	$12.3M	0.4%	+78,576	Timeline
BCAXBICARA THERAPEUTICS INC	445,975	$11.4M	0.37%	new	Timeline
ELVNENLIVEN THERAPEUTICS INC	428,571	$10.9M	0.36%	0	Timeline
NMRANEUMORA THERAPEUTICS INC.	828,101	$10.9M	0.36%	+68,094	Timeline
CYTKCYTOKINETICS INC	206,108	$10.9M	0.35%	new	Timeline
BMRNBIOMARIN PHARMACEUTICAL INC	151,000	$10.6M	0.35%	0	Timeline
PRTAPROTHENA CORP PLC	625,048	$10.5M	0.34%	0	Timeline
CMPXCOMPASS THERAPEUTICS INC	5,629,239	$10.4M	0.34%	+115,451	Timeline
KRYSKRYSTAL BIOTECH INC	55,861	$10.2M	0.33%	-49,708	Timeline
AUPHAURINIA PHARMACEUTICALS INC	1,179,740	$8.65M	0.28%	0	Timeline
JSPRJASPER THERAPEUTICS INC	459,088	$8.64M	0.28%	+54,753	Timeline
NVAXNOVAVAX INC	650,000	$8.21M	0.27%	-25,000	Timeline
XNCRXENCOR INC	401,013	$8.06M	0.26%	new	Timeline
NEVRO CORPNEVRO CORP	1,381,500	$7.72M	0.25%	0
DVAXDYNAVAX TECHNOLOGIES CORP	605,013	$6.74M	0.22%	-687,624	Timeline
SPRINGWORKS THERAPEUTICS INCSPRINGWORKS THERAPEUTICS INC	199,855	$6.4M	0.21%	0
BHVNBIOHAVEN LTD	127,558	$6.37M	0.21%	0	Timeline
BEAMBEAM THERAPEUTICS INC	249,923	$6.12M	0.2%	0	Timeline
PCRXPACIRA BIOSCIENCES INC	400,000	$6.02M	0.2%	-385,000	Timeline
NAMSNEWAMSTERDAM PHARMA COMPANY	353,319	$5.87M	0.19%	new	Timeline
Mersana Therapeutics IncMersana Therapeutics Inc	3,046,782	$5.76M	0.19%	0
LUNGPULMONX CORP	691,300	$5.73M	0.19%	+38,900	Timeline
ABOSACUMEN PHARMACEUTICALS INC	2,300,059	$5.7M	0.19%	0	Timeline
CATXPERSPECTIVE THERAPEUTICS INC	414,396	$5.53M	0.18%	+13,200	Timeline
PLRXPLIANT THERAPEUTICS INC	384,996	$4.32M	0.14%	0	Timeline
ESSA PHARMA INCESSA PHARMA INC	677,005	$4.1M	0.13%	0
FOCLEDAP TMS S A	1,568,000	$4M	0.13%	+93,000	Timeline
AUTLAUTOLUS THERAPEUTICS LTD	1,032,988	$3.75M	0.12%	0	Timeline
MGNXMACROGENICS INC	1,053,647	$3.47M	0.11%	0	Timeline
CYPHCYPHERPUNK TECHNOLOGIES INC	1,266,546	$3.26M	0.11%	0	Timeline
GOSSGOSSAMER BIO INC	3,266,960	$3.22M	0.1%	0	Timeline
ACRSACLARIS THERAPEUTICS INC	2,753,495	$3.17M	0.1%	0	Timeline
XLOXilio Therapeutics Inc.	3,003,259	$2.37M	0.08%	0	Timeline
APLSAPELLIS PHARMACEUTICALS INC	80,000	$2.31M	0.08%	-60,700	Timeline
ADAPYADAPTIMMUNE THERAPEUTICS PLC S	2,425,468	$2.31M	0.07%	0	Timeline
SGMTSAGIMET BIOSCIENCES INC	787,808	$2.18M	0.07%	0	Timeline
BMEABIOMEA FUSION INC	181,147	$1.83M	0.06%	0	Timeline
CGENCOMPUGEN LTD	989,990	$1.79M	0.06%	0	Timeline
VIGIL NEUROSCIENCE INCVIGIL NEUROSCIENCE INC	471,958	$1.6M	0.05%	0
SPRUCE BIOSCIENCES INCSPRUCE BIOSCIENCES INC	2,609,125	$1.24M	0.04%	0
KRROKORRO BIO INC	35,719	$1.19M	0.04%	0	Timeline
KYTXKYVERNA THERAPEUTICS INC	178,963	$875K	0.03%	0	Timeline
ALLAKOS INCALLAKOS INC	1,200,409	$784K	0.03%	0
VINCERX PHARMA INCVINCERX PHARMA INC	891,719	$638K	0.02%	0
ACCOLADE INCACCOLADE INC	160,217	$617K	0.02%	-2,129,783
TLPHTALPHERA INC	316,460	$271K	0.01%	0	Timeline
NUVATION BIO INC -CW27NUVATION BIO INC -CW27	134,028	$13.1K	<0.01%	0

Principal amounts

Notes and convertibles filed as a face amount (PRN). A face amount is never added to a share count (H6).

Security	Type	Amount	Value	Change
GOSSAMER BIO INCGOSSAMER BIO INC NOTE 5.000% 6/0	principal	9,573,000	$5.01M	0
NEVRO CORPNEVRO CORP NOTE 2.750% 4/0	principal	500,000	$484K	0

Sold out in Q3 2024

Positions in the previous quarter's report that this quarter's report no longer lists.

Security	Shares before	Value before	Type
IDXXIDEXX LABS INC	119,500	$58.2M	shares
IMCRIMMUNOCORE HLDGS PLC	419,030	$14.2M	shares
OLINK HLDG ABOLINK HLDG AB	500,000	$12.7M	shares
CRLCHARLES RIV LABS INTL INC	60,250	$12.4M	shares
BLUEPRINT MEDICINES CORPBLUEPRINT MEDICINES CORP	57,000	$6.14M	call
FULCFULCRUM THERAPEUTICS INC	727,673	$4.51M	shares
MLYSMINERALYS THERAPEUTICS INC	378,932	$4.43M	shares
TRAVERE THERAPEUTICS INCTRAVERE THERAPEUTICS INC	3,250,000	$2.89M	principal
GPCRSTRUCTURE THERAPEUTICS INC	65,600	$2.58M	call

How Q3 2024 was built

Available 13F filings of this filer for the quarter and their roles: the base report is the latest original or restatement, NEW HOLDINGS amendments filed after it are added (method).

Filing	Role	Amendment	Filed	Accepted	Ingested
13F-HR 0001172661-24-004721	base		2024-11-14	acceptance time not in the bulk data set	2026-10-07 18:26:56 UTC