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	66,663	1,350,000	SH		SOLE		1,350,000	0	0
ACADIA PHARMACEUTICALS INC	COM	004225108	4,853	174,000	SH		SOLE		174,000	0	0
ACHILLION PHARMACEUTICALS IN	COM	00448Q201	7,918	1,725,000	SH		SOLE		1,725,000	0	0
ACLARIS THERAPEUTICS INC	COM	00461U105	11,933	440,000	SH		SOLE		440,000	0	0
ADAPTIMMUNE THERAPEUTICS PLC	SPONDS ADR	00653A107	3,929	875,000	SH		SOLE		875,000	0	0
ADURO BIOTECH INC	COM	00739L101	4,731	415,000	SH		SOLE		415,000	0	0
ADVANCED ACCELERATOR APPLIC	SPONSORED ADS	00790T100	32,794	840,000	SH		SOLE		840,000	0	0
AEGLEA BIOTHERAPEUTICS INC	COM	00773J103	2,013	524,089	SH		SOLE		524,089	0	0
AETNA INC NEW	COM	00817Y108	58,910	388,000	SH		SOLE		388,000	0	0
AIMMUNE THERAPEUTICS INC	COM	00900T107	6,024	293,000	SH		SOLE		293,000	0	0
ALDER BIOPHARMACEUTICALS INC	COM	014339105	2,084	182,000	SH		SOLE		182,000	0	0
ALEXION PHARMACEUTICALS INC	COM	015351109	56,333	463,000	SH		SOLE		463,000	0	0
ALIGN TECHNOLOGY INC	COM	016255101	3,453	23,000	SH		SOLE		23,000	0	0
ALKERMES PLC	SHS	G01767105	3,014	52,000	SH		SOLE		52,000	0	0
ALLERGAN PLC	SHS	G0177J108	37,898	155,900	SH		SOLE		155,900	0	0
ALLERGAN PLC	PFD CONV SER A	G0177J116	4,336	5,000	SH		SOLE		5,000	0	0
ALMOST FAMILY INC	COM	020409108	22,317	362,000	SH		SOLE		362,000	0	0
ALNYLAM PHARMACEUTICALS INC	COM	02043Q107	8,375	105,000	SH		SOLE		105,000	0	0
AMARIN CORP PLC	SPONS ADR NEW	023111206	17,128	4,250,000	SH		SOLE		4,250,000	0	0
AMICUS THERAPEUTICS INC	COM	03152W109	7,628	757,500	SH		SOLE		757,500	0	0
ANTHERA PHARMACEUTICALS INC	COM	03674U300	268	165,705	SH		SOLE		165,705	0	0
ARDELYX INC	COM	039697107	10,200	2,000,000	SH		SOLE		2,000,000	0	0
ASCENDIS PHARMA A S	SPONSORED ADR	04351P101	9,022	325,000	SH		SOLE		325,000	0	0
ASSEMBLY BIOSCIENCES INC	COM	045396108	8,054	390,000	SH		SOLE		390,000	0	0
ATYR PHARMA INC	COM	002120103	1,615	475,000	SH		SOLE		475,000	0	0
AUDENTES THERAPEUTICS INC	COM	05070R104	11,386	595,200	SH		SOLE		595,200	0	0
AVEXIS INC	COM	05366U100	14,378	175,000	SH		SOLE		175,000	0	0
AXOGEN INC	COM	05463X106	6,281	375,000	SH		SOLE		375,000	0	0
AXOVANT SCIENCES LTD	COM	G0750W104	2,899	125,000	SH		SOLE		125,000	0	0
BARD C R INC	COM	067383109	18,176	57,500	SH		SOLE		57,500	0	0
BAXTER INTL INC	COM	071813109	13,924	230,000	SH		SOLE		230,000	0	0
BEIGENE LTD	SPONSORED ADR	07725L102	11,925	265,000	SH		SOLE		265,000	0	0
BIOGEN INC	COM	09062X103	14,382	53,000	SH		SOLE		53,000	0	0
BIOHAVEN PHARMACTL HLDG CO L	COM	G11196105	7,675	307,000	SH		SOLE		307,000	0	0
BIOMARIN PHARMACEUTICAL INC	COM	09061G101	11,353	125,000	SH		SOLE		125,000	0	0
BLUEBIRD BIO INC	COM	09609G100	3,362	32,000	SH		SOLE		32,000	0	0
BRISTOL MYERS SQUIBB CO	COM	110122108	2,786	50,000	SH		SOLE		50,000	0	0
CARDIOME PHARMA CORP	COM NO PAR	14159U301	5,424	1,200,000	SH		SOLE		1,200,000	0	0
CELGENE CORP	COM	151020104	31,818	245,000	SH		SOLE		245,000	0	0
CERULEAN PHARMA INC	COM	15708Q105	276	625,000	SH		SOLE		625,000	0	0
CHIASMA INC	COM	16706W102	714	492,500	SH		SOLE		492,500	0	0
CHINA CORD BLOOD CORP	SHS	G21107100	8,342	880,000	SH		SOLE		880,000	0	0
CIDARA THERAPEUTICS INC	COM	171757107	2,250	300,000	SH		SOLE		300,000	0	0
CIGNA CORPORATION	COM	125509109	45,195	270,000	SH		SOLE		270,000	0	0
CLEARSIDE BIOMEDICAL INC	COM	185063104	8,518	935,000	SH		SOLE		935,000	0	0
CLOVIS ONCOLOGY INC	COM	189464100	21,675	231,500	SH		SOLE		231,500	0	0
COHERUS BIOSCIENCES INC	COM	19249H103	9,957	693,900	SH		SOLE		693,900	0	0
COLLEGIUM PHARMACEUTICAL INC	COM	19459J104	22,495	1,798,195	SH		SOLE		1,798,195	0	0
COMPUGEN LTD	ORD	M25722105	3,135	825,000	SH		SOLE		825,000	0	0
CORVUS PHARMACEUTICALS INC	COM	221015100	5,113	422,600	SH		SOLE		422,600	0	0
DANAHER CORP DEL	COM	235851102	18,988	225,000	SH		SOLE		225,000	0	0
DBV TECHNOLOGIES S A	SPONSORED ADR	23306J101	2,607	73,000	SH		SOLE		73,000	0	0
DERMIRA INC	COM	24983L104	11,295	387,600	SH		SOLE		387,600	0	0
DIMENSION THERAPEUTICS INC	COM	25433V105	393	271,370	SH		SOLE		271,370	0	0
DYNAVAX TECHNOLOGIES CORP	COM NEW	268158201	1,592	165,000	SH		SOLE		165,000	0	0
EDWARDS LIFESCIENCES CORP	COM	28176E108	22,466	190,001	SH		SOLE		190,001	0	0
EGALET CORP	COM	28226B104	711	300,000	SH		SOLE		300,000	0	0
EGALET CORP	NOTE 5.500% 4/0	28226BAB0	5,002	7,800,000	PRN		SOLE		7,800,000	0	0
EPIZYME INC	COM	29428V104	17,743	1,175,000	SH		SOLE		1,175,000	0	0
EXACT SCIENCES CORP	COM	30063P105	15,474	437,500	SH		SOLE		437,500	0	0
EXELIXIS INC	COM	30161Q104	4,310	175,000	SH		SOLE		175,000	0	0
FIBROGEN INC	COM	31572Q808	9,044	280,000	SH		SOLE		280,000	0	0
FIVE PRIME THERAPEUTICS INC	COM	33830X104	5,932	197,000	SH		SOLE		197,000	0	0
G1 THERAPEUTICS INC	COM	3621LQ109	5,445	312,188	SH		SOLE		312,188	0	0
GALAPAGOS NV	SPON ADR	36315X101	16,949	221,500	SH		SOLE		221,500	0	0
GENOCEA BIOSCIENCES INC	COM	372427104	2,506	480,000	SH		SOLE		480,000	0	0
GILEAD SCIENCES INC	COM	375558103	22,182	313,400	SH		SOLE		313,400	0	0
GLAUKOS CORP	COM	377322102	2,592	62,500	SH		SOLE		62,500	0	0
GLOBAL BLOOD THERAPEUTICS IN	COM	37890U108	4,103	150,000	SH		SOLE		150,000	0	0
GLYCOMIMETICS INC	COM	38000Q102	2,511	225,000	SH		SOLE		225,000	0	0
GW PHARMACEUTICALS PLC	ADS	36197T103	36,641	365,500	SH		SOLE		365,500	0	0
HEALTHEQUITY INC	COM	42226A107	2,541	51,000	SH		SOLE		51,000	0	0
HEALTHSOUTH CORP	COM NEW	421924309	12,826	265,000	SH		SOLE		265,000	0	0
HILL ROM HLDGS INC	COM	431475102	3,582	45,000	SH		SOLE		45,000	0	0
HOLOGIC INC	COM	436440101	19,060	420,000	SH		SOLE		420,000	0	0
HUMANA INC	COM	444859102	31,882	132,500	SH		SOLE		132,500	0	0
INCYTE CORP	COM	45337C102	21,782	173,000	SH		SOLE		173,000	0	0
INFINITY PHARMACEUTICALS INC	COM	45665G303	424	270,000	SH		SOLE		270,000	0	0
INNOVIVA INC	COM	45781M101	2,560	200,000	SH		SOLE		200,000	0	0
INSMED INC	COM PAR $.01	457669307	8,031	468,000	SH		SOLE		468,000	0	0
INTERSECT ENT INC	COM	46071F103	9,643	345,000	SH		SOLE		345,000	0	0
INTRA CELLULAR THERAPIES INC	COM	46116X101	2,329	187,500	SH		SOLE		187,500	0	0
INTUITIVE SURGICAL INC	COM NEW	46120E602	44,898	48,000	SH		SOLE		48,000	0	0
INVITAE CORP	COM	46185L103	11,472	1,200,000	SH		SOLE		1,200,000	0	0
JAZZ PHARMACEUTICALS PLC	SHS USD	G50871105	19,235	123,700	SH		SOLE		123,700	0	0
JOHNSON & JOHNSON	COM	478160104	23,151	175,000	SH		SOLE		175,000	0	0
JUNO THERAPEUTICS INC	COM	48205A109	6,725	225,000	SH		SOLE		225,000	0	0
KITE PHARMA INC	COM	49803L109	6,998	67,500	SH		SOLE		67,500	0	0
LEXICON PHARMACEUTICALS INC	COM NEW	528872302	6,473	393,500	SH	Call	SOLE		393,500	0	0
LOXO ONCOLOGY INC	COM	548862101	23,095	288,000	SH		SOLE		288,000	0	0
MACROGENICS INC	COM	556099109	3,940	225,000	SH		SOLE		225,000	0	0
MADRIGAL PHARMACEUTICALS INC	COM	558868105	8,780	540,000	SH		SOLE		540,000	0	0
MEDICINES CO	COM	584688105	26,396	694,446	SH		SOLE		694,446	0	0
MEDICINES CO	NOTE 2.500% 1/1	584688AE5	3,913	3,000,000	PRN		SOLE		3,000,000	0	0
MEDICINES CO	NOTE 2.750% 7/1	584688AG0	5,256	5,000,000	PRN		SOLE		5,000,000	0	0
MEDTRONIC PLC	SHS	G5960L103	35,500	400,000	SH		SOLE		400,000	0	0
MERCK & CO INC	COM	58933Y105	48,580	758,000	SH		SOLE		758,000	0	0
MERSANA THERAPEUTICS INC	COM	59045L106	21,345	1,527,893	SH		SOLE		1,527,893	0	0
MERUS N V	COM	N5749R100	6,372	402,000	SH		SOLE		402,000	0	0
MOLINA HEALTHCARE INC	COM	60855R100	18,229	263,500	SH		SOLE		263,500	0	0
MYOVANT SCIENCES LTD	COM	G637AM102	1,755	150,000	SH		SOLE		150,000	0	0
NABRIVA THERAPEUTICS PLC	SHS	G63637105	5,502	525,000	SH		SOLE		525,000	0	0
NEUROCRINE BIOSCIENCES INC	COM	64125C109	19,274	419,000	SH		SOLE		419,000	0	0
NEURODERM LTD	ORD SHS	M74231107	7,107	237,700	SH		SOLE		237,700	0	0
NEWLINK GENETICS CORP	COM	651511107	533	72,500	SH		SOLE		72,500	0	0
NIVALIS THERAPEUTICS INC	COM	65481J109	1,446	600,000	SH		SOLE		600,000	0	0
NOVADAQ TECHNOLOGIES INC	COM	66987G102	1,758	150,000	SH		SOLE		150,000	0	0
NOVAVAX INC	COM	670002104	943	820,000	SH		SOLE		820,000	0	0
OBSEVA SA	COM	H5861P103	7,182	840,000	SH		SOLE		840,000	0	0
OREXIGEN THERAPEUTICS INC	COM NEW	686164302	479	165,300	SH		SOLE		165,300	0	0
OTONOMY INC	COM	68906L105	3,959	210,000	SH		SOLE		210,000	0	0
PACIRA PHARMACEUTICALS INC	COM	695127100	49,727	1,042,500	SH		SOLE		1,042,500	0	0
PARATEK PHARMACEUTICALS INC	COM	699374302	14,460	600,000	SH		SOLE		600,000	0	0
PENUMBRA INC	COM	70975L107	27,246	310,500	SH		SOLE		310,500	0	0
PERRIGO CO PLC	SHS	G97822103	740	9,800	SH		SOLE		9,800	0	0
PORTOLA PHARMACEUTICALS INC	COM	737010108	7,847	139,700	SH		SOLE		139,700	0	0
PORTOLA PHARMACEUTICALS INC	COM	737010108	7,864	140,000	SH	Call	SOLE		140,000	0	0
PRA HEALTH SCIENCES INC	COM	69354M108	34,692	462,500	SH		SOLE		462,500	0	0
PROTEOSTASIS THERAPEUTICS IN	COM	74373B109	2,106	450,000	SH		SOLE		450,000	0	0
PROTHENA CORP PLC	SHS	G72800108	16,750	309,500	SH		SOLE		309,500	0	0
PUMA BIOTECHNOLOGY INC	COM	74587V107	16,256	186,000	SH		SOLE		186,000	0	0
RA PHARMACEUTICALS INC	COM	74933V108	11,244	600,000	SH		SOLE		600,000	0	0
RADIUS HEALTH INC	COM NEW	750469207	41,171	910,250	SH		SOLE		910,250	0	0
REGENERON PHARMACEUTICALS	COM	75886F107	7,858	16,000	SH		SOLE		16,000	0	0
RETROPHIN INC	COM	761299106	7,756	400,000	SH		SOLE		400,000	0	0
RIGEL PHARMACEUTICALS INC	COM NEW	766559603	2,730	1,000,000	SH		SOLE		1,000,000	0	0
RTI SURGICAL INC	COM	74975N105	11,408	1,950,000	SH		SOLE		1,950,000	0	0
SAREPTA THERAPEUTICS INC	COM	803607100	6,911	205,000	SH		SOLE		205,000	0	0
SCYNEXIS INC	COM	811292101	1,360	760,000	SH		SOLE		760,000	0	0
SEATTLE GENETICS INC	COM	812578102	5,174	100,000	SH		SOLE		100,000	0	0
SERES THERAPEUTICS INC	COM	81750R102	2,486	220,000	SH		SOLE		220,000	0	0
SPARK THERAPEUTICS INC	COM	84652J103	37,338	625,000	SH		SOLE		625,000	0	0
STERIS PLC	SHS USD	G84720104	5,909	72,500	SH		SOLE		72,500	0	0
TANDEM DIABETES CARE INC	COM	875372104	450	562,500	SH		SOLE		562,500	0	0
TESARO INC	COM	881569107	68,601	490,500	SH		SOLE		490,500	0	0
TETRAPHASE PHARMACEUTICALS I	COM	88165N105	4,977	698,000	SH		SOLE		698,000	0	0
THERAPEUTICSMD INC	COM	88338N107	8,432	1,600,000	SH		SOLE		1,600,000	0	0
THERAVANCE BIOPHARMA INC	NOTE 3.250%11/0	88339KAA0	2,032	1,500,000	PRN		SOLE		1,500,000	0	0
THERAVANCE BIOPHARMA INC	COM	G8807B106	23,904	600,000	SH		SOLE		600,000	0	0
THERMO FISHER SCIENTIFIC INC	COM	883556102	19,192	110,000	SH		SOLE		110,000	0	0
ULTRAGENYX PHARMACEUTICAL IN	COM	90400D108	9,969	160,500	SH		SOLE		160,500	0	0
UNITEDHEALTH GROUP INC	COM	91324P102	58,222	314,000	SH		SOLE		314,000	0	0
VERTEX PHARMACEUTICALS INC	COM	92532F100	16,624	129,000	SH		SOLE		129,000	0	0
WALGREENS BOOTS ALLIANCE INC	COM	931427108	6,735	86,000	SH		SOLE		86,000	0	0
WELLCARE HEALTH PLANS INC	COM	94946T106	35,463	197,500	SH		SOLE		197,500	0	0
WILLIS TOWERS WATSON PUB LTD	SHS	G96629103	16,001	110,000	SH		SOLE		110,000	0	0
WRIGHT MED GROUP INC	NOTE 2.000% 2/1	98235TAE7	1,116	1,000,000	PRN		SOLE		1,000,000	0	0
WRIGHT MED GROUP N V	ORD SHS 0.03 PAR	N96617118	18,418	670,000	SH		SOLE		670,000	0	0
ZIMMER BIOMET HLDGS INC	COM	98956P102	2,709	21,100	SH		SOLE		21,100	0	0