| OPEN | Opendoor Technologies Inc - Common Stock | | |
| OPENL | Opendoor Technologies Inc - Series A Warrants, each whole warrant exercisable to purchase one share of Common Stock at an exercise price of $13.00 per warrant | | |
| OPENW | Opendoor Technologies Inc - Series K Warrants, each whole warrant exercisable to purchase one share of Common Stock at an exercise price of $9.00 per warrant | | |
| OPENZ | Opendoor Technologies Inc - Series Z Warrants, each whole warrant exercisable to purchase one share of Common Stock at an exercise price of $17.00 per warrant | | |
| OPI | Office Properties Income Trust - Common shares of beneficial interest | | |
| OPK | Opko Health, Inc. - Common Stock | | |
| OPNW | OpenWorld, Inc. - Common Stock | | |
| OPRA | Opera Limited - American Depositary Shares | | |
| OPRT | Oportun Financial Corporation - common stock | | |
| OPRX | OptimizeRx Corporation - Common Stock | | |
| OPTH | Optimi Health Corp. - Common Shares | | |
| OPTX | Syntec Optics Holdings, Inc. - Class A Common Stock | | |
| OPTXW | Syntec Optics Holdings, Inc. - Warrant | | |
| OPXS | Optex Systems Holdings, Inc. - Common Stock | | |
| ORBS | Eightco Holdings Inc. - Common Stock | | |
| ORGO | Organogenesis Holdings Inc. - Class A | | |
| ORIC | Oric Pharmaceuticals, Inc. - Common Stock | | |
| ORIO | Orion Digital Corp. - Common Shares | | |
| ORIQ | Origin Investment Corp I - Ordinary Shares | | |
| ORIQU | Origin Investment Corp I - Units | | |
| ORIQW | Origin Investment Corp I - Redeemable Warrant | | |
| ORKA | Oruka Therapeutics, Inc. - Common Stock | | |
| ORKT | Orangekloud Technology Inc. - Class A Ordinary Shares | | |
| ORLY | O'Reilly Automotive, Inc. - Common Stock | | SP500 |
| ORMP | Oramed Pharmaceuticals Inc. - Common Stock | | |
| ORRF | Orrstown Financial Services, Inc. - Common Stock | | |
| OSBC | Old Second Bancorp, Inc. - Common Stock | | |
| OSIS | OSI Systems, Inc. - Common Stock | | |
| OSPN | OneSpan Inc. - Common Stock | | |
| OSPR | Osprey Acquisition Corp. III - Class A Ordinary Shares | | |
| OSPRU | Osprey Acquisition Corp. III - Units | | |
| OSPRW | Osprey Acquisition Corp. III - Warrants | | |
| OSS | One Stop Systems, Inc. - Common Stock | | |
| OST | Ostin Technology Group Co., Ltd. - Class A Ordinary Shares | | |
| OSUR | OraSure Technologies, Inc. - Common Stock | | |
| OSW | OneSpaWorld Holdings Limited - Common Shares | | |
| OTEX | Open Text Corporation - Common Shares | | |
| OTGA | OTG Acquisition Corp. I - Class A Ordinary Share | | |
| OTGAU | OTG Acquisition Corp. I - Unit | | |
| OTGAW | OTG Acquisition Corp. I - Warrants | | |
| OTLK | Outlook Therapeutics, Inc. - Common Stock | D | |
| OTLY | Oatly Group AB - American Depositary Shares | | |
| OTTR | Otter Tail Corporation - Common Stock | | |
| OUST | Ouster, Inc. - Common Stock | | |
| OVBC | Ohio Valley Banc Corp. - Common Stock | | |
| OVID | Ovid Therapeutics Inc. - Common Stock | | |
| OVLY | Oak Valley Bancorp (CA) - Common Stock | | |
| OWLS | OBOOK Holdings Inc. - Class A Common Shares | | |
| OXBR | Oxbridge Re Holdings Limited - Ordinary Shares | | |
| OXBRW | Oxbridge Re Holdings Limited - Warrant | | |