GROUP ONE TRADING, L.P. Information

440 S. LASALLE STREET, CHICAGO, Illinois, 60605, (312) 347-8864

Report Date: 12/31/2013

Position Statistics

Total Positions 1,866
New Positions 491
Increased Positions 1,006
Decreased Positions 832
Positions with Activity 1,838
Sold Out Positions 408
Total Mkt Value (in $ millions) 905

Institutional Holdings information is filed by major institutions on form 13-F with the Securities and Exchange Commission.

Sector Weighting

Basic Materials 4.53%
Capital Goods 2.13%
Conglomerates 1.03%
Consumer Cyclical 2.68%
Consumer/Non-Cyclical 1.81%
Energy 15.12%
Financial 9.69%
Healthcare 13.61%
Services 21.24%
Technology 21.02%
Transportation 2.36%
Utilities 3.41%

1,866 Positions as of 12/31/2013

Company ▲ Class Value of Shares ($1,000s) Change in Value ($1,000s) Change (%) Shares Held
21VIANET GROUP INC SPONSORED ADR 291 -745 (71.91) 11,112
3-D SYS CORP DEL COM NEW 2,558 1,152 81.88 53,111
3M CO COM 28 28 New 200
51JOB INC SP ADR REP COM -28 Sold Out 0
58 COM INC SPON ADR REP A 336 336 New 7,816
AAR CORP COM 210 -28 (11.89) 7,831
AASTROM BIOSCIENCES INC COM PAR$ 7.69 14
ABBVIE INC COM 3,707 -859 (18.82) 76,344
ABRAXAS PETE CORP COM 282 100 54.95 54,834
ACACIA RESH CORP ACACIA TCH COM 61 -637 (91.29) 3,563
ACADIA HEALTHCARE COMPANY INC COM 471 176 59.79 11,390
ACADIA PHARMACEUTICALS COM 9,168 1,665 22.18 471,604
ACCESS MIDSTREAM PARTNERS L P UNIT -33 Sold Out 0
ACCO BRANDS CORP COM 4 4 New 700
ACCRETIVE HEALTH INC COM 273 256 1,486.64 29,210
ACCURAY INC COM 1,829 850 86.73 203,024
ACCURIDE CORP NEW COM NEW 17 1 5.88 3,600
ACELRX PHARMACEUTICALS INC COM 179 25 16.55 16,747
ACETO CORP COM -40 Sold Out 0
ACHILLION PHARMACEUTICALS INC COM 1,797 1,797 New 634,972