| Code | Name | High | Low | Close | Volume | Change |
| OBAS | Optibase Ltd. | 1.290 | 1.290 | 1.290 | 100 | 0.020 |  | 1.53 |
| OBCI | Ocean Bio-Chem Inc. | 0.9000 | 0.8600 | 0.9000 | 985 | 0.0400 |  | 4.65 |
| OCCF | Optical Cable Corporation | 3.000 | 2.830 | 3.000 | 600 | 0.000 |  | 0.00 |
| OCFC | OceanFirst Financial Corp. | 10.52 | 10.19 | 10.45 | 58,040 | 0.01 |  | 0.10 |
| OCLR | Ocular Sciences, Inc. | 1.350 | 1.300 | 1.340 | 875,316 | 0.020 |  | 1.47 |
| OCLS | Oculus Innovative Sciences Inc. | 1.490 | 1.400 | 1.400 | 100,153 | 0.030 |  | 2.10 |
| OCNF | OceanFreight Inc. | 1.170 | 1.110 | 1.130 | 2,562,061 | 0.010 |  | 0.88 |
| OCNW | Occam Networks Inc. | 3.950 | 3.660 | 3.930 | 64,869 | 0.190 |  | 5.08 |
| ODFL | Old Dominion Freight Line Inc. | 28.05 | 27.44 | 27.65 | 267,181 | 0.13 |  | 0.47 |
| ODSY | Odyssey Healthcare Inc. | 15.12 | 14.87 | 15.00 | 247,991 | 0.02 |  | 0.13 |
| OESX | Orion Energy Systems Inc. | 3.890 | 3.550 | 3.570 | 121,921 | 0.180 |  | 4.80 |
| OFIX | Orthofix International N.V. | 30.61 | 29.66 | 29.77 | 45,681 | 0.88 |  | 2.87 |
| OFLX | Omega Flex Inc. | 17.38 | 16.13 | 16.80 | 46,948 | 0.20 |  | 1.20 |
| OGXI | Oncogenex Technologies Inc. | 32.77 | 31.06 | 32.32 | 68,324 | 0.18 |  | 0.56 |
| OICO | O. I. Corporation | 7.400 | 7.070 | 7.250 | 400 | 0.150 |  | 2.03 |
| OIIM | O2Micro International | 4.500 | 4.330 | 4.380 | 68,621 | 0.090 |  | 2.01 |
| OKSB | Southwest Bancorp Inc. | 7.950 | 7.560 | 7.670 | 30,100 | 0.020 |  | 0.26 |
| OKSBP | Southwest Bancorp Inc. | 27.00 | 27.00 | 27.00 | 100 | 0.00 |  | 0.00 |
| OLBK | Old Line Bancshares Inc. | 6.740 | 6.490 | 6.500 | 10,700 | 0.250 |  | 4.00 |
| OLCB | Ohio Legacy Corporation | 1.450 | 0.900 | 1.250 | 32,695 | 0.050 |  | 4.17 |
| OMAB | Grupo Aeroportuario del Centro Norte | 12.15 | 11.78 | 11.94 | 12,376 | 0.05 |  | 0.42 |
| OMCL | Omnicell Inc. | 10.33 | 10.07 | 10.20 | 107,854 | 0.09 |  | 0.89 |
| OMER | OMEROS CORPORATION | 7.840 | 7.150 | 7.500 | 95,960 | 0.200 |  | 2.60 |
| OMEX | Odyssey Marine Exploration Inc. | 1.560 | 1.500 | 1.530 | 165,868 | 0.030 |  | 2.00 |
| OMNI | OMNI Energy Services Corp. | 1.0300 | 1.0000 | 1.0000 | 56,945 | 0.0400 |  | 3.85 |
| OMPI | Obagi Medical Products Inc. | 11.05 | 10.39 | 10.76 | 46,231 | 0.02 |  | 0.19 |
| OMTR | Omniture Inc. | 22.43 | 21.42 | 21.52 | 10,325,742 | 0.04 |  | 0.19 |
| ONAV | Omega Navigation Enterprises Inc. | 3.930 | 3.750 | 3.840 | 55,370 | 0.090 |  | 2.29 |
| ONCY | Oncolytics Biotech Inc. | 2.790 | 2.690 | 2.700 | 165,828 | 0.090 |  | 3.23 |
| ONEQ | Fidelity Nasdaq Composite Index Tracking | 84.70 | 84.23 | 84.55 | 7,836 | 0.55 |  | 0.65 |
| ONFC | Oneida Financial Corp. | 8.850 | 8.590 | 8.850 | 500 | 0.150 |  | 1.72 |
| ONNN | ON Semiconductor Corporation | 7.840 | 7.640 | 7.730 | 6,991,317 | 0.130 |  | 1.65 |
| ONSM | Onstream Media Corporation | 0.3300 | 0.3100 | 0.3100 | 5,650 | 0.0000 |  | 0.00 |
| ONTY | Oncothyreon Inc . | 4.700 | 4.560 | 4.700 | 113,620 | 0.040 |  | 0.86 |
| ONVI | Onvia Inc. | 6.080 | 5.650 | 6.070 | 500 | 0.130 |  | 2.19 |
| ONXX | ONYX Pharmaceuticals Inc. | 28.05 | 27.25 | 27.99 | 831,797 | 0.10 |  | 0.36 |
| OPEN | Open Solutions, Inc. | 27.11 | 26.25 | 26.98 | 134,038 | 0.01 |  | 0.04 |
| OPHC | OptimumBank Holdings Inc. | 2.090 | 2.050 | 2.050 | 900 | 0.350 |  | 14.58 |
| OPLK | Oplink Communications Inc. | 17.79 | 17.30 | 17.76 | 213,004 | 0.16 |  | 0.91 |
| OPMR | Optimal Group Inc. | 2.190 | 2.030 | 2.170 | 13,222 | 0.120 |  | 5.85 |
| OPMRD | OPTIMAL GROUP INC | 2.990 | 2.800 | 2.800 | 7,136 | 0.090 |  | 3.11 |
| OPNT | OPNET Technologies Inc. | 10.70 | 10.39 | 10.40 | 38,527 | 0.17 |  | 1.61 |
| OPOF | Old Point Financial Corporation | 16.50 | 15.36 | 16.17 | 12,244 | 0.30 |  | 1.89 |
| OPTC | Optelecom-NKF Inc. | 2.180 | 2.010 | 2.100 | 7,685 | 0.080 |  | 3.96 |
| OPTR | Optimer Pharmaceuticals Inc. | 12.18 | 11.89 | 12.00 | 214,265 | 0.01 |  | 0.08 |
| OPTT | Ocean Power Technologies Inc. | 10.410 | 9.520 | 9.880 | 304,823 | 0.460 |  | 4.45 |
| OPTV | OpenTV Corp. | 1.540 | 1.470 | 1.500 | 539,747 | 0.030 |  | 1.96 |
| OPWV | Openwave Systems Inc | 2.510 | 2.370 | 2.400 | 500,482 | 0.030 |  | 1.23 |
| OPXA | Opexa Therapeutics Inc. | 2.100 | 2.000 | 2.050 | 58,658 | 0.010 |  | 0.49 |
| OPXAW | Opexa Therapeutics Inc. | 0.9800 | 0.9500 | 0.9800 | 6,600 | 0.0200 |  | 2.00 |
| OPXT | Opnext Inc. | 1.900 | 1.830 | 1.880 | 168,173 | 0.030 |  | 1.62 |
| ORBC | ORBCOMM Inc. | 2.500 | 2.440 | 2.480 | 47,723 | 0.040 |  | 1.64 |
| ORBK | Orbotech Ltd. | 10.16 | 9.84 | 10.10 | 50,900 | 0.04 |  | 0.40 |
| ORBT | Orbit International Corporation | 3.940 | 3.580 | 3.940 | 8,813 | 0.240 |  | 6.49 |
| ORCC | Online Resources Corporation | 5.480 | 5.270 | 5.480 | 84,980 | 0.140 |  | 2.62 |
| ORCD | Orchard Enterprises Inc (The) | 1.650 | 1.590 | 1.650 | 10,700 | 0.050 |  | 2.94 |
| ORCH | Orchid Cellmark Inc. | 1.600 | 1.530 | 1.570 | 6,721 | 0.000 |  | 0.00 |
| ORCL | Oracle Corporation | 22.39 | 22.18 | 22.34 | 24,493,905 | 0.05 |  | 0.22 |
| ORCT | Orckit Communications | 3.510 | 3.420 | 3.470 | 9,418 | 0.030 |  | 0.86 |
| OREX | Orexigen Therapeutics Inc. | 7.210 | 6.820 | 6.870 | 943,050 | 0.230 |  | 3.24 |
| ORIT | Oritani Financial Corp. | 12.71 | 12.54 | 12.68 | 15,321 | 0.05 |  | 0.40 |
| ORLY | O'Reilly Automotive Inc. | 39.15 | 38.51 | 38.90 | 1,354,778 | 0.07 |  | 0.18 |
| ORNG | Orange 21 Inc. | 0.7100 | 0.7100 | 0.7100 | 4,600 | 0.0000 |  | 0.00 |
| ORRF | ORRSTOWN FINL SVCS INC | 32.90 | 30.88 | 31.00 | 7,707 | 1.23 |  | 3.82 |
| ORXE | Ore Pharmaceuticals Inc | 0.6400 | 0.5300 | 0.5300 | 33,322 | 0.1000 |  | 15.87 |
| OSBC | Old Second Bancorp Inc. | 6.290 | 5.720 | 5.970 | 58,458 | 0.230 |  | 3.71 |
| OSBCP | Old Second Bancorp Inc. | 4.850 | 4.650 | 4.700 | 18,600 | 0.050 |  | 1.08 |
| OSBK | Osage Bancshares Inc. | 7.770 | 7.690 | 7.750 | 800 | 0.020 |  | 0.26 |
| OSHC | Ocean Shore Holding Co. | 8.010 | 8.000 | 8.000 | 5,204 | 0.220 |  | 2.83 |
| OSIP | OSI Pharmaceuticals Inc. | 33.05 | 32.50 | 32.79 | 346,990 | 0.07 |  | 0.21 |
| OSIR | Osiris Therapeutics Inc. | 6.640 | 6.490 | 6.570 | 178,608 | 0.090 |  | 1.39 |
| OSIS | OSI Systems Inc. | 19.23 | 18.95 | 19.15 | 69,012 | 0.06 |  | 0.31 |
| OSTE | Osteotech Inc. | 3.270 | 3.010 | 3.040 | 54,484 | 0.240 |  | 7.32 |
| OSTK | Overstock.com Inc. | 15.77 | 15.45 | 15.73 | 55,068 | 0.19 |  | 1.22 |
| OSUR | OraSure Technologies Inc. | 4.240 | 4.100 | 4.150 | 122,963 | 0.030 |  | 0.72 |
| OTEX | Open Text Corporation | 36.50 | 35.82 | 36.36 | 350,675 | 0.26 |  | 0.71 |
| OTIV | On Track Innovations Ltd | 1.100 | 1.060 | 1.100 | 29,337 | 0.010 |  | 0.92 |
| OTIX | OTIX GLOBAL INC | 0.9300 | 0.8800 | 0.9300 | 6,100 | 0.0000 |  | 0.00 |
| OTT | Otelco Inc. | 13.99 | 13.85 | 13.95 | 32,726 | 0.28 |  | 2.05 |
| OTTR | Otter Tail Corporation | 23.72 | 23.08 | 23.22 | 93,470 | 0.19 |  | 0.81 |
| OUTD | Outdoor Channel Holdings Inc. | 6.320 | 6.020 | 6.100 | 32,584 | 0.000 |  | 0.00 |
| OVBC | Ohio Valley Banc Corp. | 21.34 | 20.65 | 21.25 | 3,806 | 0.22 |  | 1.05 |
| OVLY | OAK VALLEY BANCORP | 4.750 | 4.500 | 4.750 | 600 | 0.250 |  | 5.56 |
| OVRL | Overland Storage Inc. | 0.9000 | 0.7300 | 0.8000 | 146,327 | 0.0600 |  | 8.11 |
| OVTI | OmniVision Technologies Inc. | 12.98 | 12.54 | 12.66 | 537,424 | 0.21 |  | 1.63 |
| OXGN | OXiGENE Inc. | 1.250 | 1.200 | 1.250 | 108,079 | 0.060 |  | 5.04 |
| OXPS | optionsXpress Holdings Inc. | 16.33 | 15.89 | 15.99 | 219,606 | 0.23 |  | 1.42 |
| OYOG | OYO Geospace Corporation | 31.68 | 29.54 | 30.86 | 17,852 | 0.02 |  | 0.06 |
| OZRK | Bank of the Ozarks | 26.77 | 26.23 | 26.54 | 162,284 | 0.11 |  | 0.42 |