Atika 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
Estimated average burden
hours per response:		23.8

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
2U INC	COM	90214J101	1,768	21,153	SH		SOLE		21,153	0	0
2U INC	COM	90214J101	3,915	46,847	SH		DFND	1	46,847	0	0
ACTIVISION BLIZZARD INC	COM	00507V109	942	12,339	SH		DFND	1	12,339	0	0
ACTIVISION BLIZZARD INC	COM	00507V109	432	5,661	SH		SOLE		5,661	0	0
ADVANSIX INC	COM	00773T101	2,379	64,957	SH		DFND	1	64,957	0	0
ADVANSIX INC	COM	00773T101	1,100	30,043	SH		SOLE		30,043	0	0
AERIE PHARMACEUTICALS INC	COM	00771V108	3,695	54,700	SH	Call	DFND	1	54,700	0	0
AERIE PHARMACEUTICALS INC	COM	00771V108	1,709	25,300	SH	Call	SOLE		25,300	0	0
ALIGN TECHNOLOGY INC	COM	016255101	6,316	18,461	SH		DFND	1	18,461	0	0
ALIGN TECHNOLOGY INC	COM	016255101	2,922	8,539	SH		SOLE		8,539	0	0
ALNYLAM PHARMACEUTICALS INC	COM	02043Q107	1,553	15,770	SH		DFND	1	15,770	0	0
ALNYLAM PHARMACEUTICALS INC	COM	02043Q107	712	7,230	SH		SOLE		7,230	0	0
AMAZON COM INC	COM	023135106	3,089	1,817	SH		SOLE		1,817	0	0
AMAZON COM INC	COM	023135106	6,685	3,933	SH		DFND	1	3,933	0	0
ARENA PHARMACEUTICALS INC	COM NEW	040047607	5,667	129,977	SH		DFND	1	129,977	0	0
ARENA PHARMACEUTICALS INC	COM NEW	040047607	2,617	60,023	SH		SOLE		60,023	0	0
ARENA PHARMACEUTICALS INC	COM NEW	040047607	558	12,800	SH	Call	DFND	1	12,800	0	0
ARENA PHARMACEUTICALS INC	COM NEW	040047607	257	5,900	SH	Call	SOLE		5,900	0	0
ARGENX SE	SPONSORED ADR	04016X101	3,401	41,047	SH		DFND	1	41,047	0	0
ARGENX SE	SPONSORED ADR	04016X101	1,571	18,963	SH		SOLE		18,963	0	0
ARISTA NETWORKS INC	COM	040413106	1,222	4,744	SH		SOLE		4,744	0	0
ARISTA NETWORKS INC	COM	040413106	2,641	10,256	SH		DFND	1	10,256	0	0
ASCENDIS PHARMA A S	SPONSORED ADR	04351P101	328	4,932	SH		SOLE		4,932	0	0
ASCENDIS PHARMA A S	SPONSORED ADR	04351P101	716	10,768	SH		DFND	1	10,768	0	0
ASHLAND GLOBAL HLDGS INC	COM	044186104	4,556	58,282	SH		DFND	1	58,282	0	0
ASHLAND GLOBAL HLDGS INC	COM	044186104	2,089	26,718	SH		SOLE		26,718	0	0
ATLASSIAN CORP PLC	CL A	G06242104	3,847	61,532	PRN		DFND	1	61,532	0	0
ATLASSIAN CORP PLC	CL A	G06242104	1,780	28,468	PRN		SOLE		28,468	0	0
AUTODESK INC	COM	052769106	4,494	34,282	SH		DFND	1	34,282	0	0
AUTODESK INC	COM	052769106	2,060	15,718	SH		SOLE		15,718	0	0
BIOHAVEN PHARMACTL HLDG CO L	COM	G11196105	2,027	51,300	SH	Call	DFND	1	51,300	0	0
BIOHAVEN PHARMACTL HLDG CO L	COM	G11196105	937	23,700	SH	Call	SOLE		23,700	0	0
BIOMARIN PHARMACEUTICAL INC	COM	09061G101	3,683	39,100	SH	Call	DFND	1	39,100	0	0
BIOMARIN PHARMACEUTICAL INC	COM	09061G101	1,677	17,800	SH	Call	SOLE		17,800	0	0
BLUEBIRD BIO INC	COM	09609G100	905	5,766	SH		SOLE		5,766	0	0
BLUEBIRD BIO INC	COM	09609G100	1,999	12,734	SH		DFND	1	12,734	0	0
BRISTOL MYERS SQUIBB CO	COM	110122108	2,856	51,600	SH	Call	DFND	1	51,600	0	0
BRISTOL MYERS SQUIBB CO	COM	110122108	1,295	23,400	SH	Call	SOLE		23,400	0	0
CIGNA CORPORATION	COM	125509109	2,923	17,200	SH	Call	DFND	1	17,200	0	0
CIGNA CORPORATION	COM	125509109	1,326	7,800	SH	Call	SOLE		7,800	0	0
CRISPR THERAPEUTICS AG	NAMEN AKT	H17182108	370	6,300	SH	Call	SOLE		6,300	0	0
CRISPR THERAPEUTICS AG	NAMEN AKT	H17182108	2,089	35,558	SH		DFND	1	35,558	0	0
CRISPR THERAPEUTICS AG	NAMEN AKT	H17182108	966	16,442	SH		SOLE		16,442	0	0
CRISPR THERAPEUTICS AG	NAMEN AKT	H17182108	805	13,700	SH	Call	DFND	1	13,700	0	0
CRITEO S A	SPONS ADS	226718104	306	9,300	SH	Put	SOLE		9,300	0	0
CRITEO S A	SPONS ADS	226718104	680	20,700	SH	Put	DFND	1	20,700	0	0
DEXCOM INC	COM	252131107	4,871	51,282	SH		DFND	1	51,282	0	0
DEXCOM INC	COM	252131107	2,253	23,718	SH		SOLE		23,718	0	0
DEXCOM INC	COM	252131107	2,602	27,400	SH	Call	DFND	1	27,400	0	0
DEXCOM INC	COM	252131107	1,197	12,600	SH	Call	SOLE		12,600	0	0
DINE BRANDS GLOBAL INC	COM	254423106	2,558	34,200	SH	Call	DFND	1	34,200	0	0
DINE BRANDS GLOBAL INC	COM	254423106	1,182	15,800	SH	Call	SOLE		15,800	0	0
DOCUSIGN INC	COM	256163106	2,606	49,200	SH	Put	DFND	1	49,200	0	0
DOCUSIGN INC	COM	256163106	1,208	22,800	SH	Put	SOLE		22,800	0	0
ENDOCYTE INC	COM	29269A102	2,791	202,264	SH		DFND	1	202,264	0	0
ENDOCYTE INC	COM	29269A102	1,280	92,736	SH		SOLE		92,736	0	0
EPAM SYS INC	COM	29414B104	1,368	11,003	SH		SOLE		11,003	0	0
EPAM SYS INC	COM	29414B104	2,984	23,997	SH		DFND	1	23,997	0	0
ETSY INC	COM	29786A106	6,277	148,790	SH		DFND	1	148,790	0	0
ETSY INC	COM	29786A106	2,878	68,210	SH		SOLE		68,210	0	0
EXACT SCIENCES CORP	COM	30063P105	4,824	80,682	SH		DFND	1	80,682	0	0
EXACT SCIENCES CORP	COM	30063P105	2,231	37,318	SH		SOLE		37,318	0	0
FACEBOOK INC	CL A	30303M102	5,450	28,044	SH		DFND	1	28,044	0	0
FACEBOOK INC	CL A	30303M102	2,518	12,956	SH		SOLE		12,956	0	0
FIVE BELOW INC	COM	33829M101	1,019	10,428	SH		SOLE		10,428	0	0
FIVE BELOW INC	COM	33829M101	2,206	22,572	SH		DFND	1	22,572	0	0
FLOOR & DECOR HLDGS INC	CL A	339750101	858	17,392	SH		SOLE		17,392	0	0
FLOOR & DECOR HLDGS INC	CL A	339750101	1,855	37,608	SH		DFND	1	37,608	0	0
GALAPAGOS NV	SPON ADR	36315X101	3,725	40,396	SH		DFND	1	40,396	0	0
GALAPAGOS NV	SPON ADR	36315X101	1,715	18,604	SH		SOLE		18,604	0	0
GRACE W R & CO DEL NEW	COM	38388F108	4,495	61,314	SH		DFND	1	61,314	0	0
GRACE W R & CO DEL NEW	COM	38388F108	2,030	27,686	SH		SOLE		27,686	0	0
GRACE W R & CO DEL NEW	COM	38388F108	7,793	106,300	SH	Call	DFND	1	106,300	0	0
GRACE W R & CO DEL NEW	COM	38388F108	3,570	48,700	SH	Call	SOLE		48,700	0	0
HUBSPOT INC	COM	443573100	5,632	44,916	SH		DFND	1	44,916	0	0
HUBSPOT INC	COM	443573100	2,581	20,584	SH		SOLE		20,584	0	0
ICU MED INC	COM	44930G107	3,714	12,649	SH		DFND	1	12,649	0	0
ICU MED INC	COM	44930G107	1,718	5,851	SH		SOLE		5,851	0	0
INOGEN INC	COM	45780L104	1,195	6,414	SH		SOLE		6,414	0	0
INOGEN INC	COM	45780L104	2,438	13,086	SH		DFND	1	13,086	0	0
INSPIRE MED SYS INC	COM	457730109	2,133	59,825	SH		DFND	1	59,825	0	0
INSPIRE MED SYS INC	COM	457730109	987	27,675	SH		SOLE		27,675	0	0
INSULET CORP	COM	45784P101	3,702	43,201	SH		DFND	1	43,201	0	0
INSULET CORP	COM	45784P101	1,697	19,799	SH		SOLE		19,799	0	0
INTUITIVE SURGICAL INC	COM NEW	46120E602	5,887	12,304	SH		DFND	1	12,304	0	0
INTUITIVE SURGICAL INC	COM NEW	46120E602	2,725	5,696	SH		SOLE		5,696	0	0
INVESCO QQQ TR	UNIT SER 1	46090E103	52,816	307,700	SH	Put	DFND	1	307,700	0	0
INVESCO QQQ TR	UNIT SER 1	46090E103	24,426	142,300	SH	Put	SOLE		142,300	0	0
IRONWOOD PHARMACEUTICALS INC	COM CL A	46333X108	985	51,542	SH		SOLE		51,542	0	0
IRONWOOD PHARMACEUTICALS INC	COM CL A	46333X108	2,150	112,458	SH		DFND	1	112,458	0	0
ISHARES TR	LATN AMER 40 ETF	464287390	2,030	68,600	SH	Put	DFND	1	68,600	0	0
ISHARES TR	LATN AMER 40 ETF	464287390	929	31,400	SH	Put	SOLE		31,400	0	0
ISHARES TR	MSCI EMG MKT ETF	464287234	1,482	34,200	SH	Put	DFND	1	34,200	0	0
ISHARES TR	MSCI EMG MKT ETF	464287234	685	15,800	SH	Put	SOLE		15,800	0	0
LIBERTY MEDIA CORP DELAWARE	COM C BRAVES GRP	531229888	8,139	314,719	SH		DFND	1	314,719	0	0
LIBERTY MEDIA CORP DELAWARE	COM C BRAVES GRP	531229888	3,740	144,637	SH		SOLE		144,637	0	0
LIBERTY MEDIA CORP DELAWARE	COM SER C FRMLA	531229854	1,017	27,400	SH	Call	DFND	1	27,400	0	0
LIBERTY MEDIA CORP DELAWARE	COM SER C FRMLA	531229854	468	12,600	SH	Call	SOLE		12,600	0	0
LIBERTY MEDIA CORP DELAWARE	COM SER C FRMLA	531229854	1,645	44,291	SH		SOLE		44,291	0	0
LIBERTY MEDIA CORP DELAWARE	COM SER C FRMLA	531229854	3,554	95,709	SH		DFND	1	95,709	0	0
LOXO ONCOLOGY INC	COM	548862101	1,097	6,326	SH		SOLE		6,326	0	0
LOXO ONCOLOGY INC	COM	548862101	2,372	13,674	SH		DFND	1	13,674	0	0
MADRIGAL PHARMACEUTICALS INC	COM	558868105	5,069	18,125	SH		DFND	1	18,125	0	0
MADRIGAL PHARMACEUTICALS INC	COM	558868105	2,342	8,374	SH		SOLE		8,374	0	0
MARTIN MARIETTA MATLS INC	COM	573284106	3,827	17,136	SH		DFND	1	17,136	0	0
MARTIN MARIETTA MATLS INC	COM	573284106	1,756	7,864	SH		SOLE		7,864	0	0
MEDICINES CO	COM	584688105	2,022	55,100	SH	Call	SOLE		55,100	0	0
MEDICINES CO	COM	584688105	271	7,397	SH		DFND	1	7,397	0	0
MEDICINES CO	COM	584688105	125	3,416	SH		SOLE		3,416	0	0
MEDICINES CO	COM	584688105	4,401	119,900	SH	Call	DFND	1	119,900	0	0
MICROSOFT CORP	COM	594918104	2,806	28,459	SH		SOLE		28,459	0	0
MICROSOFT CORP	COM	594918104	6,069	61,541	SH		DFND	1	61,541	0	0
MOMENTA PHARMACEUTICALS INC	COM	60877T100	1,248	61,028	SH		DFND	1	61,028	0	0
MOMENTA PHARMACEUTICALS INC	COM	60877T100	572	27,972	SH		SOLE		27,972	0	0
NETFLIX INC	COM	64110L106	8,756	22,370	SH		DFND	1	22,370	0	0
NETFLIX INC	COM	64110L106	3,965	10,130	SH		SOLE		10,130	0	0
NOVOCURE LTD	ORD SHS	G6674U108	1,926	61,538	SH		DFND	1	61,538	0	0
NOVOCURE LTD	ORD SHS	G6674U108	891	28,462	SH		SOLE		28,462	0	0
OKTA INC	CL A	679295105	4,248	84,344	SH		DFND	1	84,344	0	0
OKTA INC	CL A	679295105	1,947	38,656	SH		SOLE		38,656	0	0
PENUMBRA INC	COM	70975L107	2,125	15,385	SH		DFND	1	15,385	0	0
PENUMBRA INC	COM	70975L107	983	7,115	SH		SOLE		7,115	0	0
PIVOTAL SOFTWARE INC	COM CL A	72582H107	2,494	102,778	SH		SOLE		102,778	0	0
PIVOTAL SOFTWARE INC	COM CL A	72582H107	5,393	222,222	SH		DFND	1	222,222	0	0
PORTOLA PHARMACEUTICALS INC	COM	737010108	3,280	86,839	SH		DFND	1	86,839	0	0
PORTOLA PHARMACEUTICALS INC	COM	737010108	1,517	40,161	SH		SOLE		40,161	0	0
PUMA BIOTECHNOLOGY INC	COM	74587V107	2,507	42,392	SH		DFND	1	42,392	0	0
PUMA BIOTECHNOLOGY INC	COM	74587V107	1,160	19,608	SH		SOLE		19,608	0	0
Q2 HLDGS INC	COM	74736L109	1,619	28,376	SH		DFND	1	28,376	0	0
Q2 HLDGS INC	COM	74736L109	749	13,124	SH		SOLE		13,124	0	0
RED HAT INC	COM	756577102	212	1,581	SH		SOLE		1,581	0	0
RED HAT INC	COM	756577102	459	3,419	SH		DFND	1	3,419	0	0
RINGCENTRAL INC	CL A	76680R206	2,388	33,947	SH		SOLE		33,947	0	0
RINGCENTRAL INC	CL A	76680R206	5,210	74,053	SH		DFND	1	74,053	0	0
ROKU INC	COM CL A	77543R102	4,664	109,435	SH		DFND	1	109,435	0	0
ROKU INC	COM CL A	77543R102	2,155	50,565	SH		SOLE		50,565	0	0
SAILPOINT TECHNLGIES HLDGS I	COM	78781P105	839	34,200	SH	Put	DFND	1	34,200	0	0
SAILPOINT TECHNLGIES HLDGS I	COM	78781P105	388	15,800	SH	Put	SOLE		15,800	0	0
SAREPTA THERAPEUTICS INC	COM	803607100	6,508	49,234	SH		DFND	1	49,234	0	0
SAREPTA THERAPEUTICS INC	COM	803607100	3,009	22,766	SH		SOLE		22,766	0	0
SHAKE SHACK INC	CL A	819047101	3,168	47,863	SH		DFND	1	47,863	0	0
SHAKE SHACK INC	CL A	819047101	1,465	22,137	SH		SOLE		22,137	0	0
SIENTRA INC	COM	82621J105	2,135	109,440	SH		DFND	1	109,440	0	0
SIENTRA INC	COM	82621J105	986	50,560	SH		SOLE		50,560	0	0
SPDR SERIES TRUST	S&P BIOTECH	78464A870	6,016	63,200	SH	Put	SOLE		63,200	0	0
SPDR SERIES TRUST	S&P BIOTECH	78464A870	13,022	136,800	SH	Put	DFND	1	136,800	0	0
SPOTIFY TECHNOLOGY S A	SHS	L8681T102	2,762	16,416	SH		DFND	1	16,416	0	0
SPOTIFY TECHNOLOGY S A	SHS	L8681T102	1,276	7,584	SH		SOLE		7,584	0	0
SQUARE INC	CL A	852234103	3,794	61,543	SH		DFND	1	61,543	0	0
SQUARE INC	CL A	852234103	1,754	28,457	SH		SOLE		28,457	0	0
STARS GROUP INC	COM	85570W100	1,737	47,863	SH		DFND	1	47,863	0	0
STARS GROUP INC	COM	85570W100	804	22,137	SH		SOLE		22,137	0	0
TAKE-TWO INTERACTIVE SOFTWAR	COM	874054109	1,123	9,488	SH		SOLE		9,488	0	0
TAKE-TWO INTERACTIVE SOFTWAR	COM	874054109	2,428	20,512	SH		DFND	1	20,512	0	0
TELADOC INC	COM	87918A105	1,450	24,984	SH		SOLE		24,984	0	0
TELADOC INC	COM	87918A105	3,136	54,016	SH		DFND	1	54,016	0	0
TEMPUR SEALY INTL INC	COM	88023U101	495	10,300	SH	Call	DFND	1	10,300	0	0
TEMPUR SEALY INTL INC	COM	88023U101	226	4,700	SH	Call	SOLE		4,700	0	0
TWITTER INC	COM	90184L102	2,240	51,300	SH	Call	DFND	1	51,300	0	0
TWITTER INC	COM	90184L102	1,035	23,700	SH	Call	SOLE		23,700	0	0
UNITEDHEALTH GROUP INC	COM	91324P102	4,813	19,619	SH		DFND	1	19,619	0	0
UNITEDHEALTH GROUP INC	COM	91324P102	2,179	8,881	SH		SOLE		8,881	0	0
VEEVA SYS INC	CL A COM	922475108	1,051	13,676	SH		DFND	1	13,676	0	0
VEEVA SYS INC	CL A COM	922475108	486	6,324	SH		SOLE		6,324	0	0
VERTEX PHARMACEUTICALS INC	COM	92532F100	1,395	8,205	SH		DFND	1	8,205	0	0
VERTEX PHARMACEUTICALS INC	COM	92532F100	645	3,795	SH		SOLE		3,795	0	0
WAYFAIR INC	CL A	94419L101	1,465	12,333	SH		SOLE		12,333	0	0
WAYFAIR INC	CL A	94419L101	3,167	26,667	SH		DFND	1	26,667	0	0
WEIGHT WATCHERS INTL INC NEW	COM	948626106	8,298	82,076	SH		DFND	1	82,076	0	0
WEIGHT WATCHERS INTL INC NEW	COM	948626106	3,834	37,924	SH		SOLE		37,924	0	0
WORLD WRESTLING ENTMT INC	CL A	98156Q108	4,182	57,435	SH		DFND	1	57,435	0	0
WORLD WRESTLING ENTMT INC	CL A	98156Q108	1,934	26,565	SH		SOLE		26,565	0	0
WORLD WRESTLING ENTMT INC	CL A	98156Q108	7,719	106,000	SH	Call	DFND	1	106,000	0	0
WORLD WRESTLING ENTMT INC	CL A	98156Q108	3,568	49,000	SH	Call	SOLE		49,000	0	0
ZOGENIX INC	COM NEW	98978L204	688	15,561	SH		SOLE		15,561	0	0
ZOGENIX INC	COM NEW	98978L204	1,522	34,439	SH		DFND	1	34,439	0	0