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Institutional Investment Manager
GROUP ONE TRADING LLC
GROUP ONE TRADING LLC (CIK: 0000932540) incorporated in Delaware, located at 425 S Financial Place, Chicago, IL. Institutional holdings reported to the SEC.

Institutional Holdings (2015Q1)
Portfolio Summary: 4,755 holdings with a total value of $6,369,518,000.
#
Name
Shares
Value ($)
%
Options
Notes
51 PFSWEB INC COM STK 100 1,000 0.00%
52 EZCORP INC CL A NON VTG 152 1,000 0.00%
53 EXTREME NETWORKS INC 300 1,000 0.00% Call
54 CGG 200 1,000 0.00% Put
55 GTX INC DEL 1,000 1,000 0.00% Call
56 CHECKPOINT SYS INC 100 1,000 0.00% Put
57 MV OIL TR 55 1,000 0.00%
58 HANSEN MEDICAL INC 700 1,000 0.00%
59 CORONADO BIOSCIENCES INC 300 1,000 0.00% Put
60 LATTICE SEMICONDUCTOR CORP 200 1,000 0.00% Call
61 VICAL INC 1,000 1,000 0.00% Put
62 KEMET CORP 300 1,000 0.00% Put
63 KOPIN CORP 200 1,000 0.00%
64 WAVE SYSTEMS CORP 2,100 1,000 0.00% Call
65 Acuity Brands Inc 100 1,000 0.00% Call
66 STUDENT TRANSN INC 200 1,000 0.00% Call
67 PHARMATHENE INC 500 1,000 0.00% Call
68 ONCOGENEX PHARMACEUTICALS IN 500 1,000 0.00% Call
69 REVOLUTION LIGHTING TECHNOLO COM 961 1,000 0.00%
70 SYNCHRONOSS TECHNOLOGIES INC 26 1,000 0.00%
71 CGG 100 1,000 0.00% Call
72 COTT CORP QUE 59 1,000 0.00%
73 NTELOS HLDGS CORPCOM NEW 105 1,000 0.00%
74 MIDSTATES PETE CO INC 1,000 1,000 0.00% Call
75 HIGHER ONE HLDGS INC COM 400 1,000 0.00%
76 FLY LEASING LTD 100 1,000 0.00% Call
77 SEARS HOMETOWN & OUTLET STOR 96 1,000 0.00%
78 CHECKPOINT SYS INC 100 1,000 0.00% Call
79 SERVICESOURCE INTL INC 400 1,000 0.00% Call
80 SEACHANGE INTL INC 149 1,000 0.00%
81 WHITING USA TR I 8,000 1,000 0.00% Put
82 PIONEER ENERGY SVCS CORP 272 1,000 0.00%
83 FEMALE HEALTH CO 200 1,000 0.00% Call
84 ASSEMBLY BIOSCIENCES INC 62 1,000 0.00%
85 PERMIAN BASIN RTY TR 100 1,000 0.00% Call
86 TRAVELZOO INC 100 1,000 0.00% Put
87 LTC PPTYS INC COM 30 1,000 0.00%
88 FERRO CORP 100 1,000 0.00% Call
89 IXYS CORP 100 1,000 0.00% Call
90 VAALCO ENERGY INC 600 1,000 0.00% Call
91 CHINA AUTOMOTIVE SYS INC 155 1,000 0.00%
92 CELLCOM ISRAEL LTD 300 1,000 0.00% Call
93 NEVSUN RES LTD 200 1,000 0.00% Put
94 SKULLCANDY INC 100 1,000 0.00% Put
95 MAXLINEAR INC 100 1,000 0.00% Call
96 CECO ENVIRONMENTAL CORP 100 1,000 0.00% Call
97 SILICON GRAPHICS INTL CORP 100 1,000 0.00% Call
98 Plains Gp Hldgs Lp Npv A 18 1,000 0.00%
99 HUNTINGTON BANCSHARES INC 100 1,000 0.00% Put
100 RUBY TUESDAY INC 200 1,000 0.00% Call
Page 2 of 96

Portfolio data is normalized using SEC Form 13F filings, including the Original 13F-HR (0000932540-15-000007, filed 2015.05.14).

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.