| Code | Name | High | Low | Close | Volume | Change |
| OBAS | Optibase Ltd. | 1.210 | 1.170 | 1.210 | 3,400 | 0.050 |  | 4.31 |
| OBCI | Ocean Bio-Chem Inc. | 0.8701 | 0.8250 | 0.8699 | 3,300 | 0.0600 |  | 6.45 |
| OCCF | Optical Cable Corporation | 3.160 | 2.500 | 2.700 | 8,815 | 0.250 |  | 8.47 |
| OCFC | OceanFirst Financial Corp. | 9.720 | 9.570 | 9.690 | 81,020 | 0.060 |  | 0.62 |
| OCLR | Ocular Sciences, Inc. | 1.180 | 1.070 | 1.150 | 1,163,723 | 0.020 |  | 1.71 |
| OCLS | Oculus Innovative Sciences Inc. | 2.140 | 1.650 | 1.890 | 914,458 | 0.290 |  | 13.30 |
| OCNF | OceanFreight Inc. | 1.020 | 0.990 | 1.020 | 1,454,871 | 0.000 |  | 0.00 |
| OCNW | Occam Networks Inc. | 3.740 | 2.960 | 2.960 | 77,228 | 0.340 |  | 10.30 |
| ODFL | Old Dominion Freight Line Inc. | 24.86 | 24.10 | 24.69 | 387,851 | 0.34 |  | 1.40 |
| ODSY | Odyssey Healthcare Inc. | 14.57 | 14.00 | 14.25 | 188,762 | 0.03 |  | 0.21 |
| OESX | Orion Energy Systems Inc. | 4.010 | 3.840 | 4.010 | 99,412 | 0.160 |  | 4.16 |
| OFIX | Orthofix International N.V. | 31.75 | 30.97 | 31.35 | 104,005 | 0.44 |  | 1.38 |
| OFLX | Omega Flex Inc. | 17.89 | 16.75 | 16.85 | 19,260 | 0.88 |  | 4.96 |
| OGXI | Oncogenex Technologies Inc. | 29.60 | 28.14 | 29.39 | 99,945 | 1.00 |  | 3.52 |
| OICO | O. I. Corporation | 7.250 | 7.060 | 7.230 | 590 | 0.010 |  | 0.14 |
| OIIM | O2Micro International | 4.530 | 4.340 | 4.370 | 116,449 | 0.030 |  | 0.68 |
| OKSB | Southwest Bancorp Inc. | 8.270 | 7.850 | 7.920 | 78,909 | 0.420 |  | 5.04 |
| OKSBP | Southwest Bancorp Inc. | 27.00 | 27.00 | 27.00 | 200 | 0.50 |  | 1.89 |
| OLBK | Old Line Bancshares Inc. | 6.490 | 6.480 | 6.480 | 2,882 | 0.080 |  | 1.25 |
| OLCB | Ohio Legacy Corporation | 0.6399 | 0.5500 | 0.5501 | 6,469 | 0.0000 |  | 0.00 |
| OMAB | Grupo Aeroportuario del Centro Norte | 11.68 | 11.37 | 11.49 | 20,409 | 0.10 |  | 0.88 |
| OMCL | Omnicell Inc. | 10.33 | 9.94 | 10.12 | 62,368 | 0.03 |  | 0.30 |
| OMER | OMEROS CORPORATION | 6.850 | 6.330 | 6.850 | 44,363 | 0.150 |  | 2.24 |
| OMEX | Odyssey Marine Exploration Inc. | 1.520 | 1.470 | 1.480 | 95,035 | 0.040 |  | 2.63 |
| OMNI | OMNI Energy Services Corp. | 1.260 | 1.200 | 1.230 | 83,556 | 0.000 |  | 0.00 |
| OMPI | Obagi Medical Products Inc. | 11.44 | 10.52 | 11.23 | 89,719 | 0.64 |  | 6.04 |
| OMTR | Omniture Inc. | 22.43 | 21.42 | 21.52 | 10,325,742 | 0.04 |  | 0.19 |
| ONAV | Omega Navigation Enterprises Inc. | 3.510 | 3.430 | 3.460 | 75,570 | 0.010 |  | 0.29 |
| ONCY | Oncolytics Biotech Inc. | 3.480 | 3.290 | 3.430 | 143,698 | 0.130 |  | 3.94 |
| ONEQ | Fidelity Nasdaq Composite Index Tracking | 83.34 | 82.42 | 83.18 | 9,929 | 0.35 |  | 0.42 |
| ONFC | Oneida Financial Corp. | 9.000 | 9.000 | 9.000 | 300 | 0.270 |  | 3.09 |
| ONNN | ON Semiconductor Corporation | 7.450 | 7.130 | 7.320 | 7,440,783 | 0.030 |  | 0.41 |
| ONSM | Onstream Media Corporation | 0.3300 | 0.3000 | 0.3200 | 35,016 | 0.0100 |  | 3.23 |
| ONTY | Oncothyreon Inc . | 4.500 | 4.030 | 4.500 | 366,498 | 0.420 |  | 10.29 |
| ONVI | Onvia Inc. | 5.910 | 5.580 | 5.910 | 375 | 0.070 |  | 1.20 |
| ONXX | ONYX Pharmaceuticals Inc. | 26.76 | 26.40 | 26.60 | 1,349,028 | 0.03 |  | 0.11 |
| OPEN | Open Solutions, Inc. | 27.45 | 26.11 | 27.06 | 66,235 | 0.37 |  | 1.39 |
| OPHC | OptimumBank Holdings Inc. | 2.210 | 2.200 | 2.200 | 2,951 | 0.000 |  | 0.00 |
| OPLK | Oplink Communications Inc. | 15.82 | 15.43 | 15.70 | 155,817 | 0.10 |  | 0.63 |
| OPMR | Optimal Group Inc. | 3.050 | 2.890 | 2.891 | 5,809 | 0.230 |  | 7.37 |
| OPMRD | OPTIMAL GROUP INC | 2.990 | 2.800 | 2.800 | 7,136 | 0.090 |  | 3.11 |
| OPNT | OPNET Technologies Inc. | 10.53 | 10.14 | 10.34 | 21,932 | 0.33 |  | 3.09 |
| OPOF | Old Point Financial Corporation | 16.50 | 15.35 | 16.01 | 13,989 | 0.03 |  | 0.19 |
| OPTC | Optelecom-NKF Inc. | 3.410 | 3.180 | 3.410 | 23,766 | 0.310 |  | 10.00 |
| OPTR | Optimer Pharmaceuticals Inc. | 12.20 | 11.82 | 12.11 | 182,202 | 0.32 |  | 2.71 |
| OPTT | Ocean Power Technologies Inc. | 9.310 | 6.600 | 8.230 | 2,672,426 | 1.660 |  | 25.27 |
| OPTV | OpenTV Corp. | 1.560 | 1.540 | 1.540 | 2,655,829 | 0.010 |  | 0.65 |
| OPWV | Openwave Systems Inc | 2.110 | 2.020 | 2.070 | 367,994 | 0.020 |  | 0.98 |
| OPXA | Opexa Therapeutics Inc. | 2.179 | 2.100 | 2.150 | 109,892 | 0.050 |  | 2.38 |
| OPXAW | Opexa Therapeutics Inc. | 0.9700 | 0.8901 | 0.8901 | 1,287 | 0.0300 |  | 3.26 |
| OPXT | Opnext Inc. | 2.720 | 2.510 | 2.690 | 188,587 | 0.130 |  | 5.08 |
| ORBC | ORBCOMM Inc. | 2.400 | 2.330 | 2.380 | 20,800 | 0.030 |  | 1.28 |
| ORBK | Orbotech Ltd. | 9.250 | 8.800 | 8.970 | 115,150 | 0.250 |  | 2.71 |
| ORBT | Orbit International Corporation | 3.840 | 3.720 | 3.830 | 1,300 | 0.130 |  | 3.51 |
| ORCC | Online Resources Corporation | 5.550 | 5.310 | 5.370 | 23,898 | 0.300 |  | 5.29 |
| ORCD | Orchard Enterprises Inc (The) | 1.700 | 1.500 | 1.600 | 13,170 | 0.000 |  | 0.00 |
| ORCH | Orchid Cellmark Inc. | 1.700 | 1.640 | 1.640 | 23,479 | 0.020 |  | 1.20 |
| ORCL | Oracle Corporation | 21.58 | 21.11 | 21.42 | 22,995,064 | 0.10 |  | 0.47 |
| ORCT | Orckit Communications | 3.610 | 3.550 | 3.570 | 15,007 | 0.060 |  | 1.65 |
| OREX | Orexigen Therapeutics Inc. | 7.160 | 6.860 | 7.050 | 520,405 | 0.010 |  | 0.14 |
| ORIT | Oritani Financial Corp. | 13.26 | 13.12 | 13.20 | 10,276 | 0.12 |  | 0.90 |
| ORLY | O'Reilly Automotive Inc. | 38.76 | 37.61 | 38.44 | 3,285,072 | 0.66 |  | 1.75 |
| ORNG | Orange 21 Inc. | 0.8000 | 0.7999 | 0.7999 | 1,000 | 0.1200 |  | 17.65 |
| ORRF | ORRSTOWN FINL SVCS INC | 33.78 | 32.00 | 33.00 | 10,523 | 0.58 |  | 1.73 |
| ORXE | Ore Pharmaceuticals Inc | 0.6200 | 0.5600 | 0.6097 | 2,300 | 0.0100 |  | 1.67 |
| OSBC | Old Second Bancorp Inc. | 6.190 | 5.850 | 5.930 | 23,864 | 0.020 |  | 0.34 |
| OSBCP | Old Second Bancorp Inc. | 5.000 | 4.760 | 4.990 | 14,700 | 0.070 |  | 1.42 |
| OSBK | Osage Bancshares Inc. | 7.530 | 7.400 | 7.410 | 1,833 | 0.590 |  | 7.38 |
| OSHC | Ocean Shore Holding Co. | 7.670 | 7.660 | 7.660 | 100 | 0.360 |  | 4.93 |
| OSIP | OSI Pharmaceuticals Inc. | 33.53 | 32.51 | 33.32 | 442,033 | 0.18 |  | 0.54 |
| OSIR | Osiris Therapeutics Inc. | 6.700 | 6.260 | 6.680 | 214,209 | 0.400 |  | 6.37 |
| OSIS | OSI Systems Inc. | 20.00 | 19.57 | 19.99 | 73,648 | 0.14 |  | 0.71 |
| OSTE | Osteotech Inc. | 4.150 | 3.010 | 3.170 | 437,893 | 1.030 |  | 24.52 |
| OSTK | Overstock.com Inc. | 15.80 | 14.82 | 15.78 | 142,491 | 0.70 |  | 4.64 |
| OSUR | OraSure Technologies Inc. | 3.510 | 3.430 | 3.500 | 103,188 | 0.010 |  | 0.28 |
| OTEX | Open Text Corporation | 38.22 | 37.65 | 38.06 | 177,565 | 0.08 |  | 0.21 |
| OTIV | On Track Innovations Ltd | 1.170 | 0.990 | 1.150 | 339,943 | 0.170 |  | 17.35 |
| OTIX | OTIX GLOBAL INC | 0.8500 | 0.8300 | 0.8300 | 6,378 | 0.0000 |  | 0.00 |
| OTT | Otelco Inc. | 13.35 | 13.21 | 13.35 | 27,418 | 0.05 |  | 0.38 |
| OTTR | Otter Tail Corporation | 23.70 | 23.27 | 23.55 | 113,564 | 0.04 |  | 0.17 |
| OUTD | Outdoor Channel Holdings Inc. | 6.700 | 6.600 | 6.650 | 29,599 | 0.000 |  | 0.00 |
| OVBC | Ohio Valley Banc Corp. | 21.85 | 21.10 | 21.45 | 2,400 | 0.21 |  | 0.99 |
| OVLY | OAK VALLEY BANCORP | 4.500 | 4.500 | 4.500 | 200 | 0.000 |  | 0.00 |
| OVRL | Overland Storage Inc. | 0.7900 | 0.7300 | 0.7900 | 30,807 | 0.0000 |  | 0.00 |
| OVTI | OmniVision Technologies Inc. | 12.92 | 12.50 | 12.65 | 510,517 | 0.02 |  | 0.16 |
| OXGN | OXiGENE Inc. | 1.200 | 1.170 | 1.200 | 93,229 | 0.000 |  | 0.00 |
| OXPS | optionsXpress Holdings Inc. | 15.75 | 15.29 | 15.61 | 288,327 | 0.09 |  | 0.57 |
| OYOG | OYO Geospace Corporation | 30.53 | 29.00 | 30.29 | 30,214 | 0.67 |  | 2.26 |
| OZRK | Bank of the Ozarks | 25.60 | 24.99 | 25.43 | 152,863 | 0.28 |  | 1.11 |