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Institutional Investment Manager
Rock Springs Capital Management LP
Rock Springs Capital Management LP (CIK: 0001595725) incorporated in Delaware, located at 650 South Exeter Street, Baltimore, MD. Institutional holdings reported to the SEC.

Institutional Holdings (2016Q1)
Portfolio Summary: 128 holdings with a total value of $1,193,502,000.
#
Name
Shares
Value ($)
%
Options
Notes
1 AETNA INC NEW 411,000 46,176,000 3.87%
2 ALLERGAN PLC 171,000 45,833,000 3.84%
3 ACADIA HEALTHCARE COMPANY IN 749,500 41,305,000 3.46%
4 HCA HOLDINGS INC 430,000 33,562,000 2.81%
5 BAXALTA INC 810,000 32,724,000 2.74%
6 ALEXION PHARMACEUTIC 227,750 31,707,000 2.66%
7 PFIZER INC 1,038,300 30,775,000 2.58%
8 GILEAD SCIENCES INC 330,300 30,341,000 2.54%
9 ADVANCED ACCELERATOR APPLIC 833,000 29,172,000 2.44%
10 RADIUS HEALTH 808,500 25,419,000 2.13%
11 INTUITIVE SURGICAL INC 42,000 25,244,000 2.12%
12 CELGENE CORP 239,500 23,972,000 2.01%
13 WELLCARE HEALTH PLANS INC COM 230,000 21,333,000 1.79%
14 TEVA PHARMACEUTICAL INDS LTD 395,000 21,136,000 1.77%
15 COLLEGIUM PHARMACEUTICAL INC COM 1,145,000 20,782,000 1.74%
16 MEDICINES CO 632,000 20,079,000 1.68%
17 LILLY ELI & CO 276,000 19,875,000 1.67%
18 PACIRA BIOSCIENCES INC 326,500 17,298,000 1.45%
19 SPARK THERAPEUTICS INC 580,500 17,131,000 1.44%
20 ACLARIS THERAPEUTICS INC COM 895,500 16,970,000 1.42%
21 ANTHEM INC 121,000 16,818,000 1.41%
22 CIGNA CORPORATION 122,000 16,743,000 1.40%
23 TESARO INC 379,500 16,709,000 1.40%
24 NEUROCRINE BIOSCIE COM USD0.001 404,500 15,998,000 1.34%
25 THERMO FISHER SCIENTIFIC INC 100,200 14,187,000 1.19%
26 AMGEN INC 94,000 14,093,000 1.18%
27 BIOGEN INC 53,150 13,836,000 1.16%
28 PROTHENA CORP PLC 308,000 12,677,000 1.06%
29 MEDNAX INC 195,000 12,601,000 1.06%
30 Theravance Biopharma Inc 650,500 12,229,000 1.02%
31 MCKESSON CORP 77,500 12,187,000 1.02%
32 JAZZ PHARMACEUTICALS PLC SHS USD 85,500 11,162,000 0.94%
33 BRISTOL MYERS SQUIBB CO 170,000 10,860,000 0.91%
34 PRA HEALTH SCIENCES INC 253,000 10,818,000 0.91%
35 GW PHARMACEUTICALS PLC 147,000 10,606,000 0.89%
36 PENUMBRA INC COM 228,500 10,511,000 0.88%
37 WALGREENS BOOTS ALLIANCE INC 123,500 10,404,000 0.87%
38 THERAPEUTICSMD INC 1,575,000 10,080,000 0.84%
39 Anacor Pharmaceuticals Inc 177,500 9,487,000 0.79%
40 INCYTE 130,500 9,457,000 0.79%
41 ACHILLION PHARMACEUTICALS INC COM 1,220,000 9,418,000 0.79%
42 GALAPAGOS NV 210,000 8,782,000 0.74%
43 BIOMARIN 103,250 8,516,000 0.71%
44 ARDELYX INC COM 1,060,400 8,239,000 0.69%
45 Wright Medical Group NV 490,000 8,134,000 0.68%
46 INOVALON HLDGS INC COM CL A 427,300 7,914,000 0.66%
47 HealthSouth Corp 208,000 7,827,000 0.66%
48 INVITAE CORP 752,500 7,698,000 0.64%
49 JUNO THERAPEUTICS INCORPORATED 197,001 7,504,000 0.63%
50 ULTRAGENYX PHARMACEUTICAL INC COM 118,500 7,502,000 0.63%
Page 1 of 3

Portfolio data is normalized using SEC Form 13F filings, including the Original 13F-HR (0001172661-16-003409, filed 2016.05.16).

From 2023-01-03 onward, the SEC requires values to be reported in nearest dollars. Earlier filings reported values in thousands; therefore, positions shown as $0 in older filings may represent actual values between $0–$999.