| OSUR | OraSure Technologies, Inc. | 12.15 | Healthcare | Stocks | NMS |
| OSIS | OSI Systems, Inc. | 74.77 | Technology | Stocks | NMS |
| OSRS | OSIRIS CORPORATION | 0.00 | Industrials | Stocks | PNK |
| OSIZ | OSIZ | 28.76 | N/A | ETF | BTS |
| SIR | Select Income REIT of Benefici | N/A | N/A | Stocks | NMS |
| OSIN | OPTIMUM SOURCE INTERNATIONAL | 0.04 | Industrials | Stocks | PNK |
| OSPR | Osprey Energy Acquisition Corp. | 11.29 | N/A | Stocks | NCM |
| OSI.L | OSIRIUM TECHNOLOGIES PLC ORD 1P | 20.50 | Technology | Stocks | LSE |
| O6T.SG | Osirium Technologies PLC Regist | 0.19 | Technology | Stocks | STU |
| OSIR | OSIR | N/A | N/A | Stocks | NGM |
| OCIR | OCIR | N/A | Basic Materials | Stocks | NYQ |