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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 (2016Q4)
Portfolio Summary: 133 holdings with a total value of $1,494,403,000.
#
Name
Shares
Value ($)
%
Options
Notes
1 TESARO INC 613,500 82,503,000 5.52%
2 ALEXION PHARMACEUTIC 465,000 56,893,000 3.81%
3 AETNA INC NEW 441,000 54,688,000 3.66%
4 MERCK & CO INC 750,000 44,153,000 2.95%
5 GW PHARMACEUTICALS PLC 356,000 39,783,000 2.66%
6 ACADIA HEALTHCARE COMPANY IN 1,157,500 38,313,000 2.56%
7 ALLERGAN PLC 166,000 34,862,000 2.33%
8 RADIUS HEALTH 910,250 34,617,000 2.32%
9 CIGNA CORPORATION 252,000 33,614,000 2.25%
10 WELLCARE HEALTH PLANS INC COM 234,500 32,145,000 2.15%
11 SPARK THERAPEUTICS INC 625,000 31,188,000 2.09%
12 INTUITIVE SURGICAL INC 48,000 30,440,000 2.04%
13 ACLARIS THERAPEUTICS INC COM 1,100,000 29,854,000 2.00%
14 ARDELYX INC COM 2,000,000 28,400,000 1.90%
15 CELGENE CORP 242,500 28,069,000 1.88%
16 UNITEDHEALTH GROUP INC 165,000 26,407,000 1.77%
17 BRISTOL MYERS SQUIBB CO 450,000 26,298,000 1.76%
18 COLLEGIUM PHARMACEUTICAL INC COM 1,600,000 24,912,000 1.67%
19 ADVANCED ACCELERATOR APPLIC 930,000 24,887,000 1.67%
20 LILLY ELI & CO 325,000 23,904,000 1.60%
21 MEDICINES CO 699,500 23,741,000 1.59%
22 SHIRE PLC 137,200 23,376,000 1.56%
23 PACIRA BIOSCIENCES INC 713,000 23,030,000 1.54%
24 GILEAD SCIENCES INC 276,500 19,800,000 1.32%
25 Theravance Biopharma Inc 600,000 19,128,000 1.28%
26 PENUMBRA INC COM 295,500 18,853,000 1.26%
27 INCYTE 169,000 16,946,000 1.13%
28 PRA HEALTH SCIENCES INC 300,000 16,536,000 1.11%
29 NEUROCRINE BIOSCIE COM USD0.001 410,000 15,867,000 1.06%
30 AMARIN CORP PLC 4,991,500 15,374,000 1.03%
31 Wright Medical Group NV 667,000 15,328,000 1.03%
32 PROTHENA CORP PLC 309,500 15,224,000 1.02%
33 AMGEN INC 96,500 14,109,000 0.94%
34 COHERUS BIOSCIENCES INC COM 484,500 13,639,000 0.91%
35 JAZZ PHARMACEUTICALS PLC SHS USD 123,700 13,487,000 0.90%
36 GALAPAGOS NV 210,000 13,480,000 0.90%
37 WILLIS TOWERS WATSON PLC LTD SHS 110,000 13,451,000 0.90%
38 BIOGEN INC 47,000 13,328,000 0.89%
39 WALGREENS BOOTS ALLIANCE INC 161,000 13,324,000 0.89%
40 RA PHARMACEUTICALS INC 826,000 12,547,000 0.84%
41 DANAHER CORP DEL 160,000 12,454,000 0.83%
42 PATHEON N V SHS 400,000 11,484,000 0.77%
43 EDWARDS LIFESCIENCES CORP 120,500 11,291,000 0.76%
44 ULTRAGENYX PHARMACEUTICAL INC COM 159,750 11,232,000 0.75%
45 DERMIRA INC 362,600 10,998,000 0.74%
46 HealthSouth Corp 265,000 10,929,000 0.73%
47 HOLOGIC INC 265,000 10,632,000 0.71%
48 BIOMARIN 125,000 10,355,000 0.69%
49 THERAPEUTICSMD INC 1,720,000 9,924,000 0.66%
50 RETROPHIN INC COM 522,000 9,881,000 0.66%
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Portfolio data is normalized using SEC Form 13F filings, including the Original 13F-HR (0001172661-17-000700, filed 2017.02.14).

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.