| Code | Name | High | Low | Close | Volume | Change |
| OEF | Ishares S&p 100 Index Fund | 51.25 | 50.93 | 51.15 | 985,983 | 0.08 |  | 0.16 |
| OFI | Overhill Farms Inc. | 5.900 | 5.750 | 5.840 | 29,528 | 0.070 |  | 1.18 |
| OHB | Orleans Homebuilders Inc. | 2.050 | 1.900 | 2.050 | 9,857 | 0.000 |  | 0.00 |
| OIH | Merrill Lynch Market Oil Service HOLDRS | 119.4 | 116.4 | 117.1 | 6,847,956 | 2.7 |  | 2.25 |
| OIL | IPATH ETN CRUDE OIL | 26.12 | 25.73 | 26.03 | 638,188 | 0.20 |  | 0.76 |
| OLE | 9.25 STRIDES ORACLE | 24.45 | 24.45 | 24.45 | 700 | 0.03 |  | 0.12 |
| OLO | POWERSHARES DB CRUDE | 13.53 | 13.34 | 13.50 | 19,272 | 0.05 |  | 0.37 |
| ONT | On2 Technologies Inc. | 0.6000 | 0.5900 | 0.5900 | 440,593 | 0.0000 |  | 0.00 |
| OOK | - YAHOO! FINANCE | 29.02 | 29.00 | 29.00 | 912 | 0.22 |  | 0.75 |
| OOO | SPDR O-Strip Exchange Traded Fund | 7.010 | 6.440 | 6.590 | 41,166 | 0.080 |  | 1.23 |
| OOO.U | Stream Global Services Inc | 7.300 | 7.300 | 7.300 | 400 | 0.140 |  | 1.88 |
| OOO.W | Stream Global Services Inc | 0.6000 | 0.5000 | 0.5400 | 192,503 | 0.0300 |  | 5.26 |
| OPK | Opko Health Inc | 2.090 | 2.040 | 2.070 | 118,101 | 0.030 |  | 1.47 |
| ORS | Orsus Xelent Technolgies Inc. | 0.8000 | 0.7800 | 0.7900 | 130,626 | 0.0100 |  | 1.25 |
| OTP | Claymore Exchange-Traded Fund Trust | 22.33 | 22.29 | 22.33 | 450 | 0.26 |  | 1.15 |
| OTR | Claymore Exchange-Traded Fund Trust | 23.43 | 23.38 | 23.43 | 500 | 0.34 |  | 1.43 |