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
ABBVIE INC	COM	00287Y109	30,739	325,000	SH		SOLE		325,000	0	0
ACADIA HEALTHCARE COMPANY IN	COM	00404A109	24,640	700,000	SH		SOLE		700,000	0	0
ACHILLION PHARMACEUTICALS IN	COM	00448Q201	8,832	2,400,000	SH		SOLE		2,400,000	0	0
ACLARIS THERAPEUTICS INC	COM	00461U105	12,778	880,000	SH		SOLE		880,000	0	0
ADAPTIMMUNE THERAPEUTICS PLC	SPONDS ADR	00653A107	10,170	750,000	SH		SOLE		750,000	0	0
ADVERUM BIOTECHNOLOGIES INC	COM	00773U108	5,445	900,000	SH		SOLE		900,000	0	0
AEGLEA BIOTHERAPEUTICS INC	COM	00773J103	6,221	650,000	SH		SOLE		650,000	0	0
AGILENT TECHNOLOGIES INC	COM	00846U101	11,576	164,100	SH		SOLE		164,100	0	0
ALDER BIOPHARMACEUTICALS INC	COM	014339105	27,181	1,632,500	SH		SOLE		1,632,500	0	0
ALDER BIOPHARMACEUTICALS INC	NOTE 2.500% 2/0	014339AA3	5,362	5,000,000	PRN		SOLE		5,000,000	0	0
ALEXION PHARMACEUTICALS INC	COM	015351109	41,703	300,000	SH		SOLE		300,000	0	0
ALIGN TECHNOLOGY INC	COM	016255101	26,407	67,500	SH		SOLE		67,500	0	0
ALLAKOS INC	COM	01671P100	18,221	405,000	SH		SOLE		405,000	0	0
ALLERGAN PLC	SHS	G0177J108	3,365	17,665	SH		SOLE		17,665	0	0
ALNYLAM PHARMACEUTICALS INC	COM	02043Q107	17,198	196,500	SH		SOLE		196,500	0	0
AMARIN CORP PLC	SPONS ADR NEW	023111206	70,368	4,325,000	SH		SOLE		4,325,000	0	0
AMICUS THERAPEUTICS INC	COM	03152W109	12,090	1,000,000	SH		SOLE		1,000,000	0	0
ANAPTYSBIO INC	COM	032724106	16,462	165,000	SH		SOLE		165,000	0	0
APTINYX INC	COM	03836N103	8,833	305,000	SH		SOLE		305,000	0	0
ARDELYX INC	COM	039697107	10,986	2,525,557	SH		SOLE		2,525,557	0	0
ARENA PHARMACEUTICALS INC	COM NEW	040047607	17,258	375,000	SH		SOLE		375,000	0	0
ARGENX SE	SPONSORED ADR	04016X101	12,514	165,000	SH		SOLE		165,000	0	0
ARVINAS INC	COM	04335A105	2,531	150,000	SH		SOLE		150,000	0	0
ASCENDIS PHARMA A S	SPONSORED ADR	04351P101	17,254	243,500	SH		SOLE		243,500	0	0
ASSEMBLY BIOSCIENCES INC	COM	045396108	18,199	490,000	SH		SOLE		490,000	0	0
AUDENTES THERAPEUTICS INC	COM	05070R104	16,827	425,025	SH		SOLE		425,025	0	0
AXOGEN INC	COM	05463X106	20,027	543,474	SH		SOLE		543,474	0	0
BAXTER INTL INC	COM	071813109	22,896	297,000	SH		SOLE		297,000	0	0
BEIGENE LTD	SPONSORED ADR	07725L102	37,027	215,000	SH		SOLE		215,000	0	0
BIOCRYST PHARMACEUTICALS	COM	09058V103	5,341	700,000	SH		SOLE		700,000	0	0
BIOGEN INC	COM	09062X103	17,666	50,000	SH		SOLE		50,000	0	0
BIOHAVEN PHARMACTL HLDG CO L	COM	G11196105	9,763	260,000	SH		SOLE		260,000	0	0
BIOMARIN PHARMACEUTICAL INC	COM	09061G101	12,121	125,000	SH		SOLE		125,000	0	0
BLUEBIRD BIO INC	COM	09609G100	7,665	52,500	SH		SOLE		52,500	0	0
BLUEPRINT MEDICINES CORP	COM	09627Y109	15,612	200,000	SH		SOLE		200,000	0	0
BOSTON SCIENTIFIC CORP	COM	101137107	30,800	800,000	SH		SOLE		800,000	0	0
CELGENE CORP	COM	151020104	32,252	360,400	SH		SOLE		360,400	0	0
CHIASMA INC	COM	16706W102	1,890	525,000	SH		SOLE		525,000	0	0
CIDARA THERAPEUTICS INC	COM	171757107	1,320	300,000	SH		SOLE		300,000	0	0
CLEARSIDE BIOMEDICAL INC	COM	185063104	5,996	975,000	SH		SOLE		975,000	0	0
CLEMENTIA PHARMACEUTICALS IN	COM	185575107	3,847	345,000	SH		SOLE		345,000	0	0
CLOVIS ONCOLOGY INC	COM	189464100	7,962	271,100	SH		SOLE		271,100	0	0
COHERUS BIOSCIENCES INC	COM	19249H103	11,055	670,000	SH		SOLE		670,000	0	0
COLLEGIUM PHARMACEUTICAL INC	COM	19459J104	24,322	1,650,100	SH		SOLE		1,650,100	0	0
COMPUGEN LTD	ORD	M25722105	4,151	1,078,165	SH		SOLE		1,078,165	0	0
CORREVIO PHARMA CORP	COM	22026V105	4,824	1,200,000	SH		SOLE		1,200,000	0	0
CORVUS PHARMACEUTICALS INC	COM	221015100	4,934	575,000	SH		SOLE		575,000	0	0
CYMABAY THERAPEUTICS INC	COM	23257D103	6,799	613,604	SH		SOLE		613,604	0	0
DAVITA INC	COM	23918K108	29,261	408,500	SH		SOLE		408,500	0	0
DERMIRA INC	COM	24983L104	6,540	600,000	SH		SOLE		600,000	0	0
DERMIRA INC	NOTE 3.000% 5/1	24983LAB0	834	1,000,000	PRN		SOLE		1,000,000	0	0
DYNAVAX TECHNOLOGIES CORP	COM NEW	268158201	3,323	268,000	SH		SOLE		268,000	0	0
EDWARDS LIFESCIENCES CORP	COM	28176E108	31,338	180,000	SH		SOLE		180,000	0	0
ELANCO ANIMAL HEALTH INC	COM	28414H103	13,084	375,000	SH		SOLE		375,000	0	0
ENANTA PHARMACEUTICALS INC	COM	29251M106	7,905	92,500	SH		SOLE		92,500	0	0
ENCOMPASS HEALTH CORP	COM	29261A100	52,733	676,500	SH		SOLE		676,500	0	0
ENDOCYTE INC	COM	29269A102	15,096	850,000	SH		SOLE		850,000	0	0
EPIZYME INC	COM	29428V104	13,157	1,241,253	SH		SOLE		1,241,253	0	0
EXACT SCIENCES CORP	COM	30063P105	30,384	385,000	SH		SOLE		385,000	0	0
EXELIXIS INC	COM	30161Q104	10,543	595,000	SH		SOLE		595,000	0	0
FIBROGEN INC	COM	31572Q808	18,590	306,000	SH		SOLE		306,000	0	0
FIVE PRIME THERAPEUTICS INC	COM	33830X104	8,324	598,000	SH		SOLE		598,000	0	0
G1 THERAPEUTICS INC	COM	3621LQ109	12,187	233,073	SH		SOLE		233,073	0	0
GALAPAGOS NV	SPON ADR	36315X101	19,956	177,500	SH		SOLE		177,500	0	0
GLOBAL BLOOD THERAPEUTICS IN	COM	37890U108	5,700	150,000	SH		SOLE		150,000	0	0
GLOBAL CORD BLOOD CORPORATIO	SHS	G39342103	6,466	925,000	SH		SOLE		925,000	0	0
GTX INC DEL	COM NEW	40052B207	79	50,000	SH	Call	SOLE		50,000	0	0
GW PHARMACEUTICALS PLC	ADS	36197T103	69,096	400,000	SH		SOLE		400,000	0	0
HCA HEALTHCARE INC	COM	40412C101	63,300	455,000	SH		SOLE		455,000	0	0
HERON THERAPEUTICS INC	COM	427746102	16,616	525,000	SH		SOLE		525,000	0	0
HOMOLOGY MEDICINES INC	COM	438083107	10,744	470,000	SH		SOLE		470,000	0	0
IDEXX LABS INC	COM	45168D104	20,847	83,500	SH		SOLE		83,500	0	0
IMMUNOMEDICS INC	COM	452907108	16,143	775,000	SH		SOLE		775,000	0	0
INCYTE CORP	COM	45337C102	24,323	352,100	SH		SOLE		352,100	0	0
INFLARX NV	COM	N44821101	6,092	177,500	SH		SOLE		177,500	0	0
INOGEN INC	COM	45780L104	30,759	126,000	SH		SOLE		126,000	0	0
INSMED INC	COM PAR $.01	457669307	17,996	890,000	SH		SOLE		890,000	0	0
INSMED INC	NOTE 1.750% 1/1	457669AA7	5,073	6,000,000	PRN		SOLE		6,000,000	0	0
INTERSECT ENT INC	COM	46071F103	13,225	460,000	SH		SOLE		460,000	0	0
INTRA CELLULAR THERAPIES INC	COM	46116X101	4,069	187,500	SH		SOLE		187,500	0	0
INTUITIVE SURGICAL INC	COM NEW	46120E602	81,164	141,400	SH		SOLE		141,400	0	0
INVITAE CORP	COM	46185L103	23,422	1,400,000	SH		SOLE		1,400,000	0	0
IRHYTHM TECHNOLOGIES INC	COM	450056106	45,437	480,000	SH		SOLE		480,000	0	0
KURA ONCOLOGY INC	COM	50127T109	7,088	405,000	SH		SOLE		405,000	0	0
LA JOLLA PHARMACEUTICAL CO	COM PAR $.0001 2	503459604	5,673	281,800	SH		SOLE		281,800	0	0
LOXO ONCOLOGY INC	COM	548862101	34,675	202,981	SH		SOLE		202,981	0	0
MACROGENICS INC	COM	556099109	5,896	275,000	SH		SOLE		275,000	0	0
MADRIGAL PHARMACEUTICALS INC	COM	558868105	73,232	342,000	SH		SOLE		342,000	0	0
MEDICINES CO	COM	584688105	20,638	690,000	SH		SOLE		690,000	0	0
MEDICINES CO	NOTE 2.500% 1/1	584688AE5	3,231	3,000,000	PRN		SOLE		3,000,000	0	0
MEDICINES CO	NOTE 2.750% 7/1	584688AG0	4,560	5,000,000	PRN		SOLE		5,000,000	0	0
MENLO THERAPEUTICS INC	COM	586858102	3,251	330,000	SH		SOLE		330,000	0	0
MERSANA THERAPEUTICS INC	COM	59045L106	10,000	1,000,000	SH		SOLE		1,000,000	0	0
MIRATI THERAPEUTICS INC	COM	60468T105	11,304	240,000	SH		SOLE		240,000	0	0
MOLINA HEALTHCARE INC	COM	60855R100	81,042	545,000	SH		SOLE		545,000	0	0
MOMENTA PHARMACEUTICALS INC	COM	60877T100	12,493	475,000	SH		SOLE		475,000	0	0
MYOVANT SCIENCES LTD	COM	G637AM102	9,226	347,500	SH		SOLE		347,500	0	0
NABRIVA THERAPEUTICS PLC	SHS	G63637105	4,860	1,800,000	SH		SOLE		1,800,000	0	0
NEUROCRINE BIOSCIENCES INC	COM	64125C109	79,303	645,000	SH		SOLE		645,000	0	0
NEUROCRINE BIOSCIENCES INC	NOTE 2.250% 5/1	64125CAD1	1,707	1,000,000	PRN		SOLE		1,000,000	0	0
NOVAVAX INC	COM	670002104	6,110	3,250,000	SH		SOLE		3,250,000	0	0
NOVOCURE LTD	ORD SHS	G6674U108	1,310	25,000	SH		SOLE		25,000	0	0
OBSEVA SA	COM	H5861P103	20,194	1,120,000	SH		SOLE		1,120,000	0	0
ODONATE THERAPEUTICS INC	COM	676079106	8,453	435,500	SH		SOLE		435,500	0	0
PACIRA PHARMACEUTICALS INC	COM	695127100	63,525	1,292,479	SH		SOLE		1,292,479	0	0
PACIRA PHARMACEUTICALS INC	NOTE 2.375% 4/0	695127AD2	1,060	1,000,000	PRN		SOLE		1,000,000	0	0
PARATEK PHARMACEUTICALS INC	COM	699374302	4,365	450,000	SH		SOLE		450,000	0	0
PENUMBRA INC	COM	70975L107	35,209	235,200	SH		SOLE		235,200	0	0
PORTOLA PHARMACEUTICALS INC	COM	737010108	8,623	323,800	SH		SOLE		323,800	0	0
PRA HEALTH SCIENCES INC	COM	69354M108	31,762	288,247	SH		SOLE		288,247	0	0
PUMA BIOTECHNOLOGY INC	COM	74587V107	22,356	487,600	SH		SOLE		487,600	0	0
RA PHARMACEUTICALS INC	COM	74933V108	13,568	750,000	SH		SOLE		750,000	0	0
RADIUS HEALTH INC	COM NEW	750469207	22,562	1,267,500	SH		SOLE		1,267,500	0	0
RADIUS HEALTH INC	NOTE 3.000% 9/0	750469AA6	1,153	1,500,000	PRN		SOLE		1,500,000	0	0
RESTORBIO INC	COM	76133L103	6,056	400,000	SH		SOLE		400,000	0	0
RETROPHIN INC	COM	761299106	11,492	400,000	SH		SOLE		400,000	0	0
RHYTHM PHARMACEUTICALS INC	COM	76243J105	6,272	215,000	SH		SOLE		215,000	0	0
RIGEL PHARMACEUTICALS INC	COM NEW	766559603	13,241	4,125,000	SH		SOLE		4,125,000	0	0
RTI SURGICAL INC	COM	74975N105	8,775	1,950,000	SH		SOLE		1,950,000	0	0
SAGE THERAPEUTICS INC	COM	78667J108	6,921	49,000	SH		SOLE		49,000	0	0
SAREPTA THERAPEUTICS INC	COM	803607100	50,149	310,500	SH		SOLE		310,500	0	0
SCYNEXIS INC	COM	811292101	984	820,000	SH		SOLE		820,000	0	0
SERES THERAPEUTICS INC	COM	81750R102	1,670	220,000	SH		SOLE		220,000	0	0
SOLID BIOSCIENCES INC	COM	83422E105	4,482	95,000	SH		SOLE		95,000	0	0
SPARK THERAPEUTICS INC	COM	84652J103	29,321	537,500	SH		SOLE		537,500	0	0
SPERO THERAPEUTICS INC	COM	84833T103	5,518	525,000	SH		SOLE		525,000	0	0
STRYKER CORP	COM	863667101	31,805	179,000	SH		SOLE		179,000	0	0
TELEFLEX INC	COM	879369106	32,995	124,000	SH		SOLE		124,000	0	0
TESARO INC	COM	881569107	28,672	735,000	SH		SOLE		735,000	0	0
THERAVANCE BIOPHARMA INC	NOTE 3.250%11/0	88339KAA0	1,770	1,500,000	PRN		SOLE		1,500,000	0	0
THERAVANCE BIOPHARMA INC	COM	G8807B106	17,969	550,000	SH		SOLE		550,000	0	0
THERMO FISHER SCIENTIFIC INC	COM	883556102	23,432	96,000	SH		SOLE		96,000	0	0
TRANSLATE BIO INC	COM	89374L104	10,092	1,009,179	SH		SOLE		1,009,179	0	0
ULTRAGENYX PHARMACEUTICAL IN	COM	90400D108	15,268	200,000	SH		SOLE		200,000	0	0
UNITEDHEALTH GROUP INC	COM	91324P102	156,724	589,098	SH		SOLE		589,098	0	0
UROVANT SCIENCES LTD	SHS	G9381B108	1,200	100,000	SH		SOLE		100,000	0	0
VERTEX PHARMACEUTICALS INC	COM	92532F100	37,777	196,000	SH		SOLE		196,000	0	0
VIKING THERAPEUTICS INC	COM	92686J106	3,484	200,000	SH		SOLE		200,000	0	0
WELLCARE HEALTH PLANS INC	COM	94946T106	75,475	235,500	SH		SOLE		235,500	0	0
WEST PHARMACEUTICAL SVSC INC	COM	955306105	19,755	160,000	SH		SOLE		160,000	0	0
WRIGHT MED GROUP N V	ORD SHS 0.03 PAR	N96617118	29,020	1,000,000	SH		SOLE		1,000,000	0	0
ZAI LAB LTD	ADR	98887Q104	6,818	350,000	SH		SOLE		350,000	0	0
ZIMMER BIOMET HLDGS INC	COM	98956P102	29,581	225,000	SH		SOLE		225,000	0	0
ZOGENIX INC	COM NEW	98978L204	11,656	235,000	SH		SOLE		235,000	0	0