Rock Springs Capital Management 13F-HR Quarterly holdings report by institutional manager

The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE

OMB APPROVAL

OMB Number:		3235-0006
Expires:	Oct 31, 2018
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COLUMN 1	COLUMN 2	COLUMN 3	COLUMN 4	COLUMN 5			COLUMN 6	COLUMN 7	COLUMN 8
			VALUE	SHRS OR	SH/	PUT/	INVESTMENT	OTHER	VOTING AUTHORITY
NAME OF ISSUER	TITLE OF CLASS	CUSIP	(x$1000)	PRN AMT	PRN	CALL	DISCRETION	MANAGER	SOLE	SHARED	NONE
ACADIA HEALTHCARE COMPANY IN	COM	00404A109	62,327	1,305,000	SH		SOLE		1,305,000	0	0
ACADIA PHARMACEUTICALS INC	COM	004225108	6,856	182,000	SH		SOLE		182,000	0	0
ACHILLION PHARMACEUTICALS IN	COM	00448Q201	9,570	2,131,400	SH		SOLE		2,131,400	0	0
ACLARIS THERAPEUTICS INC	COM	00461U105	11,356	440,000	SH		SOLE		440,000	0	0
ADAPTIMMUNE THERAPEUTICS PLC	SPONDS ADR	00653A107	7,166	875,000	SH		SOLE		875,000	0	0
ADURO BIOTECH INC	COM	00739L101	4,420	415,000	SH		SOLE		415,000	0	0
ADVANCED ACCELERATOR APPLIC	SPONSORED ADS	00790T100	53,048	784,500	SH		SOLE		784,500	0	0
AEGLEA BIOTHERAPEUTICS INC	COM	00773J103	2,584	524,089	SH		SOLE		524,089	0	0
AETNA INC NEW	COM	00817Y108	63,445	399,000	SH		SOLE		399,000	0	0
AIMMUNE THERAPEUTICS INC	COM	00900T107	7,263	293,000	SH		SOLE		293,000	0	0
ALDER BIOPHARMACEUTICALS INC	COM	014339105	10,719	875,000	SH		SOLE		875,000	0	0
ALEXION PHARMACEUTICALS INC	COM	015351109	64,954	463,000	SH		SOLE		463,000	0	0
ALIGN TECHNOLOGY INC	COM	016255101	11,418	61,300	SH		SOLE		61,300	0	0
ALLERGAN PLC	PFD CONV SER A	G0177J116	3,789	5,000	SH		SOLE		5,000	0	0
ALMOST FAMILY INC	COM	020409108	19,439	362,000	SH		SOLE		362,000	0	0
ALNYLAM PHARMACEUTICALS INC	COM	02043Q107	12,336	105,000	SH		SOLE		105,000	0	0
ALPINE IMMUNE SCIENCES INC	COM	02083G100	1,740	150,000	SH		SOLE		150,000	0	0
AMARIN CORP PLC	SPONS ADR NEW	023111206	14,000	4,000,000	SH		SOLE		4,000,000	0	0
AMICUS THERAPEUTICS INC	COM	03152W109	13,723	910,000	SH		SOLE		910,000	0	0
ANAPTYSBIO INC	COM	032724106	5,243	150,000	SH		SOLE		150,000	0	0
ANTHERA PHARMACEUTICALS INC	COM	03674U300	155	107,630	SH		SOLE		107,630	0	0
ARDELYX INC	COM	039697107	11,200	2,000,000	SH		SOLE		2,000,000	0	0
ARENA PHARMACEUTICALS INC	COM NEW	040047607	5,483	215,000	SH		SOLE		215,000	0	0
ASCENDIS PHARMA A S	SPONSORED ADR	04351P101	10,150	280,000	SH		SOLE		280,000	0	0
ASSEMBLY BIOSCIENCES INC	COM	045396108	13,619	390,000	SH		SOLE		390,000	0	0
ATYR PHARMA INC	COM	002120103	2,399	475,000	SH		SOLE		475,000	0	0
AUDENTES THERAPEUTICS INC	COM	05070R104	14,705	525,000	SH		SOLE		525,000	0	0
AVEXIS INC	COM	05366U100	16,928	175,000	SH		SOLE		175,000	0	0
AXOGEN INC	COM	05463X106	7,740	400,000	SH		SOLE		400,000	0	0
BARD C R INC	COM	067383109	18,429	57,500	SH		SOLE		57,500	0	0
BAXTER INTL INC	COM	071813109	14,433	230,000	SH		SOLE		230,000	0	0
BEIGENE LTD	SPONSORED ADR	07725L102	28,969	280,000	SH		SOLE		280,000	0	0
BIOCRYST PHARMACEUTICALS	COM	09058V103	2,358	450,000	SH		SOLE		450,000	0	0
BIOGEN INC	COM	09062X103	16,595	53,000	SH		SOLE		53,000	0	0
BIOHAVEN PHARMACTL HLDG CO L	COM	G11196105	9,121	244,000	SH		SOLE		244,000	0	0
BIOMARIN PHARMACEUTICAL INC	COM	09061G101	11,634	125,000	SH		SOLE		125,000	0	0
BLUEBIRD BIO INC	COM	09609G100	4,807	35,000	SH		SOLE		35,000	0	0
BLUEPRINT MEDICINES CORP	COM	09627Y109	6,026	86,500	SH		SOLE		86,500	0	0
BRISTOL MYERS SQUIBB CO	COM	110122108	3,187	50,000	SH		SOLE		50,000	0	0
CARDIOME PHARMA CORP	COM NO PAR	14159U301	2,568	1,200,000	SH		SOLE		1,200,000	0	0
CELGENE CORP	COM	151020104	38,278	262,500	SH		SOLE		262,500	0	0
CHIASMA INC	COM	16706W102	1,256	492,500	SH		SOLE		492,500	0	0
CHINA CORD BLOOD CORP	SHS	G21107100	9,786	880,000	SH		SOLE		880,000	0	0
CIDARA THERAPEUTICS INC	COM	171757107	2,430	300,000	SH		SOLE		300,000	0	0
CIGNA CORPORATION	COM	125509109	50,474	270,000	SH		SOLE		270,000	0	0
CLEARSIDE BIOMEDICAL INC	COM	185063104	8,172	935,000	SH		SOLE		935,000	0	0
CLEMENTIA PHARMACEUTICALS IN	COM	185575107	5,827	345,000	SH		SOLE		345,000	0	0
CLOVIS ONCOLOGY INC	COM	189464100	19,076	231,500	SH		SOLE		231,500	0	0
COHERUS BIOSCIENCES INC	COM	19249H103	8,523	638,400	SH		SOLE		638,400	0	0
COLLEGIUM PHARMACEUTICAL INC	COM	19459J104	18,934	1,805,000	SH		SOLE		1,805,000	0	0
COMPUGEN LTD	ORD	M25722105	3,135	825,000	SH		SOLE		825,000	0	0
CORVUS PHARMACEUTICALS INC	COM	221015100	6,736	422,600	SH		SOLE		422,600	0	0
CYMABAY THERAPEUTICS INC	COM	23257D103	3,627	450,000	SH		SOLE		450,000	0	0
DANAHER CORP DEL	COM	235851102	19,301	225,000	SH		SOLE		225,000	0	0
DARE BIOSCIENCE INC	COM	23666P101	195	62,500	SH		SOLE		62,500	0	0
DBV TECHNOLOGIES S A	SPONSORED ADR	23306J101	3,098	73,000	SH		SOLE		73,000	0	0
DERMIRA INC	COM	24983L104	10,800	400,000	SH		SOLE		400,000	0	0
DIMENSION THERAPEUTICS INC	COM	25433V105	1,350	225,000	SH		SOLE		225,000	0	0
DYNAVAX TECHNOLOGIES CORP	COM NEW	268158201	3,548	165,000	SH		SOLE		165,000	0	0
EDWARDS LIFESCIENCES CORP	COM	28176E108	20,769	190,001	SH		SOLE		190,001	0	0
EGALET CORP	COM	28226B104	384	300,000	SH		SOLE		300,000	0	0
EGALET CORP	NOTE 5.500% 4/0	28226BAB0	4,051	7,800,000	PRN		SOLE		7,800,000	0	0
EPIZYME INC	COM	29428V104	25,718	1,350,000	SH		SOLE		1,350,000	0	0
EXACT SCIENCES CORP	COM	30063P105	20,610	437,400	SH		SOLE		437,400	0	0
EXELIXIS INC	COM	30161Q104	4,240	175,000	SH		SOLE		175,000	0	0
FIBROGEN INC	COM	31572Q808	17,485	325,000	SH		SOLE		325,000	0	0
FIVE PRIME THERAPEUTICS INC	COM	33830X104	8,906	217,700	SH		SOLE		217,700	0	0
G1 THERAPEUTICS INC	COM	3621LQ109	5,974	240,000	SH		SOLE		240,000	0	0
GALAPAGOS NV	SPON ADR	36315X101	21,775	214,000	SH		SOLE		214,000	0	0
GILEAD SCIENCES INC	COM	375558103	25,392	313,400	SH		SOLE		313,400	0	0
GLOBAL BLOOD THERAPEUTICS IN	COM	37890U108	4,658	150,000	SH		SOLE		150,000	0	0
GW PHARMACEUTICALS PLC	ADS	36197T103	37,856	373,000	SH		SOLE		373,000	0	0
HEALTHEQUITY INC	COM	42226A107	8,346	165,000	SH		SOLE		165,000	0	0
HEALTHSOUTH CORP	COM NEW	421924309	12,283	265,000	SH		SOLE		265,000	0	0
INCYTE CORP	COM	45337C102	20,196	173,000	SH		SOLE		173,000	0	0
INFINITY PHARMACEUTICALS INC	COM	45665G303	359	270,000	SH		SOLE		270,000	0	0
INSMED INC	COM PAR $.01	457669307	20,287	650,000	SH		SOLE		650,000	0	0
INTERSECT ENT INC	COM	46071F103	10,747	345,000	SH		SOLE		345,000	0	0
INTRA CELLULAR THERAPIES INC	COM	46116X101	2,959	187,500	SH		SOLE		187,500	0	0
INTUITIVE SURGICAL INC	COM NEW	46120E602	50,202	48,000	SH		SOLE		48,000	0	0
INVITAE CORP	COM	46185L103	12,237	1,306,000	SH		SOLE		1,306,000	0	0
IRHYTHM TECHNOLOGIES INC	COM	450056106	20,026	386,000	SH		SOLE		386,000	0	0
IRONWOOD PHARMACEUTICALS INC	COM CL A	46333X108	3,154	200,000	SH		SOLE		200,000	0	0
JAZZ PHARMACEUTICALS PLC	SHS USD	G50871105	18,091	123,700	SH		SOLE		123,700	0	0
JOHNSON & JOHNSON	COM	478160104	22,752	175,000	SH		SOLE		175,000	0	0
JUNO THERAPEUTICS INC	COM	48205A109	10,094	225,000	SH		SOLE		225,000	0	0
KALA PHARMACEUTICALS INC	COM	483119103	571	25,000	SH		SOLE		25,000	0	0
KITE PHARMA INC	COM	49803L109	12,227	68,000	SH		SOLE		68,000	0	0
LOXO ONCOLOGY INC	COM	548862101	26,300	285,500	SH		SOLE		285,500	0	0
MACROGENICS INC	COM	556099109	4,158	225,000	SH		SOLE		225,000	0	0
MADRIGAL PHARMACEUTICALS INC	COM	558868105	12,370	275,000	SH		SOLE		275,000	0	0
MEDICINES CO	COM	584688105	25,558	690,000	SH		SOLE		690,000	0	0
MEDICINES CO	NOTE 2.500% 1/1	584688AE5	3,801	3,000,000	PRN		SOLE		3,000,000	0	0
MEDICINES CO	NOTE 2.750% 7/1	584688AG0	5,281	5,000,000	PRN		SOLE		5,000,000	0	0
MEDTRONIC PLC	SHS	G5960L103	19,237	247,364	SH		SOLE		247,364	0	0
MERCK & CO INC	COM	58933Y105	48,535	758,000	SH		SOLE		758,000	0	0
MERSANA THERAPEUTICS INC	COM	59045L106	22,996	1,330,000	SH		SOLE		1,330,000	0	0
MERUS N V	COM	N5749R100	5,464	275,000	SH		SOLE		275,000	0	0
MOLINA HEALTHCARE INC	COM	60855R100	29,051	422,500	SH		SOLE		422,500	0	0
MYOKARDIA INC	COM	62857M105	1,714	40,000	SH		SOLE		40,000	0	0
MYOVANT SCIENCES LTD	COM	G637AM102	4,565	295,100	SH		SOLE		295,100	0	0
NABRIVA THERAPEUTICS PLC	SHS	G63637105	5,119	625,000	SH		SOLE		625,000	0	0
NEUROCRINE BIOSCIENCES INC	COM	64125C109	26,963	440,000	SH		SOLE		440,000	0	0
NEURODERM LTD	ORD SHS	M74231107	9,247	237,700	SH		SOLE		237,700	0	0
NEWLINK GENETICS CORP	COM	651511107	738	72,500	SH		SOLE		72,500	0	0
NOVAVAX INC	COM	670002104	935	820,000	SH		SOLE		820,000	0	0
OBSEVA SA	COM	H5861P103	6,838	840,000	SH		SOLE		840,000	0	0
OREXIGEN THERAPEUTICS INC	COM NEW	686164302	350	165,300	SH		SOLE		165,300	0	0
PACIRA PHARMACEUTICALS INC	COM	695127100	40,854	1,088,000	SH		SOLE		1,088,000	0	0
PARATEK PHARMACEUTICALS INC	COM	699374302	11,295	450,000	SH		SOLE		450,000	0	0
PENUMBRA INC	COM	70975L107	28,038	310,500	SH		SOLE		310,500	0	0
PORTOLA PHARMACEUTICALS INC	COM	737010108	17,495	323,800	SH		SOLE		323,800	0	0
PRA HEALTH SCIENCES INC	COM	69354M108	36,371	477,500	SH		SOLE		477,500	0	0
PROTEOSTASIS THERAPEUTICS IN	COM	74373B109	945	450,000	SH		SOLE		450,000	0	0
PROTHENA CORP PLC	SHS	G72800108	20,046	309,500	SH		SOLE		309,500	0	0
PUMA BIOTECHNOLOGY INC	COM	74587V107	39,518	330,000	SH		SOLE		330,000	0	0
RA PHARMACEUTICALS INC	COM	74933V108	8,760	600,000	SH		SOLE		600,000	0	0
RADIUS HEALTH INC	COM NEW	750469207	36,353	943,000	SH		SOLE		943,000	0	0
RADIUS HEALTH INC	NOTE 3.000% 9/0	750469AA6	1,509	1,500,000	PRN		SOLE		1,500,000	0	0
REGENERON PHARMACEUTICALS	COM	75886F107	7,154	16,000	SH		SOLE		16,000	0	0
RETROPHIN INC	COM	761299106	9,956	400,000	SH		SOLE		400,000	0	0
RIGEL PHARMACEUTICALS INC	COM NEW	766559603	2,540	1,000,000	SH		SOLE		1,000,000	0	0
RTI SURGICAL INC	COM	74975N105	8,873	1,950,000	SH		SOLE		1,950,000	0	0
SAGE THERAPEUTICS INC	COM	78667J108	2,025	32,500	SH		SOLE		32,500	0	0
SAREPTA THERAPEUTICS INC	COM	803607100	11,757	259,200	SH		SOLE		259,200	0	0
SCYNEXIS INC	COM	811292101	1,832	760,000	SH		SOLE		760,000	0	0
SEATTLE GENETICS INC	COM	812578102	6,801	125,000	SH		SOLE		125,000	0	0
SERES THERAPEUTICS INC	COM	81750R102	3,529	220,000	SH		SOLE		220,000	0	0
SPARK THERAPEUTICS INC	COM	84652J103	53,229	597,000	SH		SOLE		597,000	0	0
STERIS PLC	SHS USD	G84720104	6,542	74,000	SH		SOLE		74,000	0	0
TANDEM DIABETES CARE INC	COM	875372104	411	562,500	SH		SOLE		562,500	0	0
TESARO INC	COM	881569107	63,937	495,250	SH		SOLE		495,250	0	0
TETRAPHASE PHARMACEUTICALS I	COM	88165N105	6,498	950,000	SH		SOLE		950,000	0	0
THERAPEUTICSMD INC	COM	88338N107	8,464	1,600,000	SH		SOLE		1,600,000	0	0
THERAVANCE BIOPHARMA INC	NOTE 3.250%11/0	88339KAA0	1,844	1,500,000	PRN		SOLE		1,500,000	0	0
THERAVANCE BIOPHARMA INC	COM	G8807B106	22,064	644,400	SH		SOLE		644,400	0	0
THERMO FISHER SCIENTIFIC INC	COM	883556102	20,812	110,000	SH		SOLE		110,000	0	0
ULTRAGENYX PHARMACEUTICAL IN	COM	90400D108	8,681	163,000	SH		SOLE		163,000	0	0
UNITEDHEALTH GROUP INC	COM	91324P102	89,895	459,000	SH		SOLE		459,000	0	0
VERTEX PHARMACEUTICALS INC	COM	92532F100	23,034	151,500	SH		SOLE		151,500	0	0
WELLCARE HEALTH PLANS INC	COM	94946T106	33,919	197,500	SH		SOLE		197,500	0	0
WILLIS TOWERS WATSON PUB LTD	SHS	G96629103	17,736	115,000	SH		SOLE		115,000	0	0
WRIGHT MED GROUP INC	NOTE 2.000% 2/1	98235TAE7	1,086	1,000,000	PRN		SOLE		1,000,000	0	0
WRIGHT MED GROUP N V	ORD SHS 0.03 PAR	N96617118	17,333	670,000	SH		SOLE		670,000	0	0
ZAI LAB LTD	ADR	98887Q104	8,438	312,500	SH		SOLE		312,500	0	0
ZIMMER BIOMET HLDGS INC	COM	98956P102	2,471	21,100	SH		SOLE		21,100	0	0
ZOGENIX INC	COM NEW	98978L204	3,505	100,000	SH		SOLE		100,000	0	0