Rock Springs Capital Management LP

Baltimore, MD · CIK 1595725 · 13F filing filed 2026-08-14

SEC-registered investment adviser since 2013 · limited partnership

Assets managed$2.4bn
Staff17 · 8 in investment roles
Main clients (by assets)Private funds 100%
Private funds2 (2 hedge) · $2.4bn gross assets
Form ADV · 2026-03-24SEC adviser record

Legal entityROCK SPRINGS CAPITAL MANAGEMENT LP (US)

$2.0bn reported value +20.8% vs Q1 2026

104positions

44.0%in top 10

17 new 40 added 30 reduced 13 sold out vs Q1 2026

Holdings, Q2 2026

The small lines show how much was held over the last 4 quarters (adjusted for stock splits).

#	Security	Ticker	Shares	Value	% of portfolio	Change	Shares change
1	REVOLUTION MEDICINES INC COM RVMD	RVMD	1,105,210	$207.0m10.10%	10.10%	Reduced -104.3k	-104,255 -8.6%
2	TRAVERE THERAPEUTICS INC COM TVTX	TVTX	2,179,069	$123.8m6.04%	6.04%	Added +701.1k	+701,115 47.4%
3	ELI LILLY & CO COM LLY	LLY	98,700	$118.4m5.78%	5.78%	Unchanged
4	MADRIGAL PHARMACEUTICALS INC COM MDGL	MDGL	174,999	$94.0m4.59%	4.59%	Added +4.0k	+4,000 2.3%
5	MIRUM PHARMACEUTICALS INC COM MIRM	MIRM	798,145	$93.4m4.56%	4.56%	Reduced -13.1k	-13,149 -1.6%
6	RHYTHM PHARMACEUTICALS INC COM RYTM	RYTM	692,598	$76.9m3.75%	3.75%	Added +2.9k	+2,850 0.4%
7	KYMERA THERAPEUTICS INC COM KYMR	KYMR	453,156	$52.0m2.54%	2.54%	Reduced -43.7k	-43,715 -8.8%
8	ARGENX SE SPONSORED ADR ARGX	ARGX	52,750	$48.9m2.39%	2.39%	Reduced -45.8k	-45,750 -46.5%
9	ASCENDIS PHARMA A/S ORD SHS ASND	ASND	168,750	$45.0m2.20%	2.20%	New
10	XENON PHARMACEUTICALS INC COM XENE	XENE	683,907	$41.3m2.01%	2.01%	Reduced -79.1k	-79,113 -10.4%
11	SCHOLAR ROCK HLDG CORP COM SRRK	SRRK	715,452	$39.3m1.92%	1.92%	Reduced -24.4k	-24,364 -3.3%
12	INSMED INC COM PAR $.01 INSM	INSM	362,150	$38.6m1.88%	1.88%	Added +47.9k	+47,850 15.2%
13	PENUMBRA INC COM PEN	PEN	115,750	$36.5m1.78%	1.78%	Reduced -4.8k	-4,750 -3.9%
14	STRUCTURE THERAPEUTICS INC SPONSORED ADS GPCR	GPCR	640,317	$34.4m1.68%	1.68%	Added +100	+100 0.0%
15	ULTRAGENYX PHARMACEUTICAL IN COM RARE	RARE	967,855	$32.3m1.58%	1.58%	Reduced -250.9k	-250,918 -20.6%
16	IRHYTHM TECHNOLOGIES INC COM IRTC	IRTC	269,650	$32.1m1.57%	1.57%	Added +7.9k	+7,900 3.0%
17	INTUITIVE SURGICAL INC COM NEW ISRG	ISRG	76,460	$30.4m1.48%	1.48%	Reduced -5.5k	-5,540 -6.8%
18	AGILON HEALTH INC COM NEW AGL	AGL	262,600	$28.1m1.37%	1.37%	Added +2.6k	+2,600 1.0%
19	UNITEDHEALTH GROUP INC COM UNH	UNH	63,750	$26.5m1.29%	1.29%	Added +10.8k	+10,750 20.3%
20	CELLDEX THERAPEUTICS INC NEW COM NEW CLDX	CLDX	699,146	$26.0m1.27%	1.27%	Added +48.9k	+48,876 7.5%
21	ERASCA INC COM ERAS	ERAS	1,402,150	$25.7m1.25%	1.25%	Added +298.7k	+298,681 27.1%
22	NEUROCRINE BIOSCIENCES INC COM NBIX	NBIX	144,750	$24.4m1.19%	1.19%	Reduced -5.7k	-5,700 -3.8%
23	ENLIVEN THERAPEUTICS INC COM ELVN	ELVN	464,625	$23.6m1.15%	1.15%	Reduced -361.9k	-361,875 -43.8%
24	TENET HEALTHCARE CORP COM NEW THC	THC	125,000	$23.4m1.14%	1.14%	Unchanged
25	DEXCOM INC COM DXCM	DXCM	343,000	$23.1m1.13%	1.13%	Reduced -12.6k	-12,600 -3.5%
26	ACLARIS THERAPEUTICS INC COM ACRS	ACRS	4,330,532	$22.9m1.12%	1.12%	Reduced -142.1k	-142,118 -3.2%
27	MINIMED GROUP INC COM MMED	MMED	1,520,000	$22.7m1.11%	1.11%	Added +465.0k	+465,000 44.1%
28	BOSTON SCIENTIFIC CORP COM BSX	BSX	528,500	$22.6m1.10%	1.10%	Added +13.2k	+13,200 2.6%
29	PHARVARIS N V COM PHVS	PHVS	648,333	$22.4m1.09%	1.09%	Added +2.8k	+2,800 0.4%
30	AVALYN PHARMACEUTICALS INC COM SHS AVLN	AVLN	662,918	$21.8m1.07%	1.07%	New
31	HEMAB THERAPEUTICS HLDGS INC COM SHS COAG	COAG	575,432	$21.1m1.03%	1.03%	New
32	DYNE THERAPEUTICS INC COM DYN	DYN	942,154	$20.9m1.02%	1.02%	Reduced -30.0k	-30,044 -3.1%
33	ALNYLAM PHARMACEUTICALS INC COM ALNY	ALNY	66,750	$20.1m0.98%	0.98%	Reduced -7.2k	-7,250 -9.8%
34	COGENT BIOSCIENCES INC COM COGT	COGT	515,917	$20.0m0.97%	0.97%	Reduced -108.2k	-108,238 -17.3%
35	AGIOS PHARMACEUTICALS INC COM AGIO	AGIO	532,563	$19.8m0.96%	0.96%	Reduced -266.6k	-266,600 -33.4%
36	NEWAMSTERDAM PHARMA COMPANY ORDINARY SHARES NAMS	NAMS	582,744	$19.7m0.96%	0.96%	Reduced -6.0k	-6,050 -1.0%
37	VERA THERAPEUTICS INC CL A VERA	VERA	427,584	$18.3m0.90%	0.90%	Reduced -76.0k	-76,001 -15.1%
38	TARSUS PHARMACEUTICALS INC COM TARS	TARS	277,087	$17.4m0.85%	0.85%	Added +51.9k	+51,908 23.1%
39	HEARTFLOW INC COM HTFL	HTFL	573,500	$16.8m0.82%	0.82%	Added +1.0k	+1,000 0.2%
40	MBX BIOSCIENCES INC COM MBX	MBX	298,218	$16.5m0.80%	0.80%	Added +10.3k	+10,251 3.6%
41	CYTOKINETICS INC COM NEW CYTK	CYTK	187,980	$16.0m0.78%	0.78%	Added +142.6k	+142,616 314.4%
42	BICARA THERAPEUTICS INC COM BCAX	BCAX	535,286	$15.9m0.78%	0.78%	Added +46.2k	+46,191 9.4%
43	PARABILIS MEDICINES INC COM PBLS	PBLS	578,028	$15.8m0.77%	0.77%	New
44	ZAI LAB LTD ADR ZLAB	ZLAB	814,707	$15.5m0.76%	0.76%	Unchanged
45	DANAHER CORPORATION COM DHR	DHR	76,300	$14.5m0.71%	0.71%	Added +14.8k	+14,800 24.1%
46	TANGO THERAPEUTICS INC COM TNGX	TNGX	456,551	$14.3m0.70%	0.70%	Added +69.6k	+69,636 18.0%
47	EVOLENT HEALTH INC CL A EVH	EVH	2,500,000	$13.6m0.66%	0.66%	Reduced -175.0k	-175,000 -6.5%
48	PTC THERAPEUTICS INC COM PTCT	PTCT	162,298	$13.2m0.65%	0.65%	Added +500	+500 0.3%
49	MINERALYS THERAPEUTICS INC COM MLYS	MLYS	484,951	$13.1m0.64%	0.64%	Added +45.2k	+45,200 10.3%
50	ZENAS BIOPHARMA INC COM ZBIO	ZBIO	502,077	$12.7m0.62%	0.62%	Unchanged
51	ARDELYX INC COM ARDX	ARDX	2,241,769	$11.4m0.56%	0.56%	Reduced -57.7k	-57,704 -2.5%
52	INSPIRE MED SYS INC COM INSP	INSP	244,000	$10.9m0.53%	0.53%	Added +112.2k	+112,200 85.1%
53	BRIDGEBIO PHARMA INC COM BBIO	BBIO	144,750	$10.8m0.53%	0.53%	Added +16.5k	+16,500 12.9%
54	ALKERMES PLC SHS ALKS	ALKS	199,811	$10.5m0.51%	0.51%	Added +15.8k	+15,825 8.6%
55	SUMMIT THERAPEUTICS INC COM SMMT	SMMT	715,000	$10.4m0.51%	0.51%	Added +5.0k	+5,000 0.7%
56	AZENTA INC COM AZTA	AZTA	403,000	$10.3m0.50%	0.50%	Reduced -166.1k	-166,100 -29.2%
57	INDIVIOR PHARMACEUTICALS INC COM INDV	INDV	245,500	$10.1m0.49%	0.49%	Added +45.5k	+45,500 22.8%
58	STRYKER CORPORATION COM SYK	SYK	29,000	$9.1m0.45%	0.45%	Added +14.2k	+14,200 96.0%
59	AMYLYX PHARMACEUTICALS INC COM AMLX	AMLX	499,764	$9.0m0.44%	0.44%	Unchanged
60	CARIS LIFE SCIENCES INC COM CAI	CAI	487,500	$8.7m0.42%	0.42%	Reduced -75.5k	-75,500 -13.4%
61	OMADA HEALTH INC COM OMDA	OMDA	373,000	$8.2m0.40%	0.40%	Reduced -168.0k	-168,000 -31.1%
62	COMPASS THERAPEUTICS INC COM CMPX	CMPX	3,524,929	$7.7m0.38%	0.38%	Added +219.6k	+219,621 6.6%
63	IMMUNOME INC COM IMNM	IMNM	347,666	$7.4m0.36%	0.36%	Unchanged
64	EDAP TMS S A SPONSORED ADR FOCL	FOCL	1,386,000	$7.2m0.35%	0.35%	Added +8.0k	+8,000 0.6%
65	PHREESIA INC COM PHR	PHR	696,900	$7.2m0.35%	0.35%	Added +96.5k	+96,500 16.1%
66	OMEROS CORP COM OMER	OMER	718,499	$6.8m0.33%	0.33%	New
67	DEFINIUM THERAPEUTICS INC COM SHS DFTX	DFTX	143,187	$6.7m0.33%	0.33%	New
68	CORCEPT THERAPEUTICS INC COM CORT	CORT	72,000	$6.3m0.31%	0.31%	Added +21.8k	+21,750 43.3%
69	JANUX THERAPEUTICS INC COM JANX	JANX	367,009	$5.6m0.28%	0.28%	Unchanged
70	MOBIA MED INC COMMON STOCK MOBI	MOBI	418,200	$5.6m0.27%	0.27%	New
71	ARCUS BIOSCIENCES INC COM RCUS	RCUS	180,000	$5.5m0.27%	0.27%	Unchanged
72	THERMO FISHER SCIENTIFIC INC COM TMO	TMO	10,000	$5.0m0.24%	0.24%	Unchanged
73	TREVI THERAPEUTICS INC COM TRVI	TRVI	260,000	$4.8m0.24%	0.24%	New
74	SIONNA THERAPEUTICS INC COM SION	SION	99,429	$4.4m0.21%	0.21%	Unchanged
75	CVS HEALTH CORP COM CVS	CVS	40,000	$4.1m0.20%	0.20%	Unchanged
76	EYEPOINT PHARMACEUTICALS INC COM NEW EYPT	EYPT	268,519	$3.8m0.19%	0.19%	Added +9.8k	+9,780 3.8%
77	OCULAR THERAPEUTIX INC COM OCUL	OCUL	383,716	$3.8m0.18%	0.18%	Unchanged
78	SPYRE THERAPEUTICS INC COM NEW SYRE	SYRE	42,254	$3.8m0.18%	0.18%	New
79	TALPHERA INC COM NEW TLPH	TLPH	3,589,186	$3.7m0.18%	0.18%	Unchanged
80	ROIVANT SCIENCES LTD SHS ROIV	ROIV	101,000	$3.6m0.17%	0.17%	Added +4.0k	+4,000 4.1%
81	VAXCYTE INC COM PCVX	PCVX	60,250	$3.5m0.17%	0.17%	Unchanged
82	NEUROGENE INC COM NGNE	NGNE	106,750	$3.4m0.16%	0.16%	Added +2.4k	+2,411 2.3%
83	CENTURY THERAPEUTICS INC COM IPSC	IPSC	1,304,347	$3.2m0.16%	0.16%	Unchanged
84	ALPHATEC HLDGS INC COM NEW ATEC	ATEC	360,000	$3.1m0.15%	0.15%	Added +10.0k	+10,000 2.9%
85	NOVO-NORDISK A S ADR NVO	NVO	63,500	$3.0m0.15%	0.15%	Reduced -26.5k	-26,500 -29.4%
86	OLEMA PHARMACEUTICALS INC COM OLMA	OLMA	235,178	$2.9m0.14%	0.14%	Added +64.8k	+64,800 38.0%
87	NERVGEN PHARMA CORP COM NGEN	NGEN	1,208,231	$2.5m0.12%	0.12%	New
88	MEDTRONIC PLC SHS MDT	MDT	30,900	$2.4m0.12%	0.12%	New
89	TEVA PHARMACEUTICAL INDS LTD SPONSORED ADS SPONSORED ADS		59,000	$2.0m0.10%	0.10%	Added +13.5k	+13,500 29.7%
90	DIANTHUS THERAPEUTICS INC COM DNTH	DNTH	20,326	$2.0m0.10%	0.10%	Reduced -6.4k	-6,431 -24.0%
91	SAGIMET BIOSCIENCES INC COM SER A SGMT	SGMT	250,000	$1.9m0.09%	0.09%	New
92	CAPRICOR THERAPEUTICS INC COM NEW CAPR	CAPR	74,448	$1.8m0.09%	0.09%	New
93	LENZ THERAPEUTICS INC COM LENZ	LENZ	257,460	$1.5m0.07%	0.07%	Unchanged
94	ALTIMMUNE INC COM NEW ALT	ALT	471,465	$1.4m0.07%	0.07%	New
95	KAILERA THERAPEUTICS INC COMMON STOCK KLRA	KLRA	65,000	$1.4m0.07%	0.07%	New
96	SURGERY PARTNERS INC COM SGRY	SGRY	84,000	$1.4m0.07%	0.07%	Reduced -124.0k	-124,000 -59.6%
97	AXSOME THERAPEUTICS INC COM AXSM	AXSM	5,500	$1.3m0.07%	0.07%	New
98	ORUKA THERAPEUTICS INC COM ORKA	ORKA	12,051	$1.1m0.06%	0.06%	Added +7.9k	+7,928 192.3%
99	VIKING THERAPEUTICS INC COM VKTX	VKTX	25,500	$994.8k0.05%	0.05%	Reduced -70.5k	-70,500 -73.4%
100	LEGEND BIOTECH CORP SPONSORED ADS LEGN	LEGN	33,500	$967.5k0.05%	0.05%	Reduced -7.0k	-7,000 -17.3%

Sold out since Q1 2026

Security	Ticker	Shares held before	Value then
ASCENDIS PHARMA A/S		194,000	$44.4m194.0k shares
ARCELLX INC ACLX	ACLX	169,859	$19.5m169.9k shares
CENTESSA PHARMACEUTICALS PLC		351,828	$14.0m351.8k shares
SOLENO THERAPEUTICS INC SLNO	SLNO	257,253	$8.6m257.3k shares
REGENERON PHARMACEUTICALS REGN	REGN	10,100	$7.8m10.1k shares
APELLIS PHARMACEUTICALS INC APLS	APLS	162,750	$6.5m162.8k shares
TERNS PHARMACEUTICALS INC		113,748	$6.0m113.7k shares
SPDR SER TR XBI	XBI	30,000	$3.8m30.0k shares
EDWARDS LIFESCIENCES CORP EW	EW	28,900	$2.3m28.9k shares
ACADIA HEALTHCARE COMPANY IN ACHC	ACHC	75,500	$1.8m75.5k shares
JAZZ PHARMACEUTICALS PLC JAZZ	JAZZ	5,750	$1.1m5.8k shares
GOSSAMER BIO INC GOSS	GOSS	1,609,492	$528.7k1.6m shares
AMICUS THERAPEUTICS INC FOLD	FOLD	21,062	$304.6k21.1k shares

Stakes above 5%

Companies where this manager has reported owning more than 5% of a class of shares, on Schedule 13D (may seek influence) or 13G (passive): its latest filing for each, from 19 Dec 2024 on.

Company	Ticker	Stake	Change	Schedule	Last filed
TALPHERA INC TLPH · 13G · filed 2025-09-12	TLPH	7.9%≈ $3.7m	new	13G	2025-09-12