- ORI — Old Republic International Corporation
- ORI.AX — Orica Limited
- ORIC — ORIC Pharmaceuticals, Inc.
- ORINF — Orion Oyj
- ORINY — Orion Oyj
- ORIO — Orion Digital Corp. Common Shares
- ORIO.TO — Orion Digital Corp.
- ORIQ — Origin Investment Corp I Ordinary Shares
- ORIQU — Origin Investment Corp I Units
- ORIQW — Origin Investment Corp I Warrant.
- ORISF — Oriental Rise Holdings Ltd
- ORKA — Oruka Therapeutics, Inc.
- ORKLF — Orkla ASA
- ORKLY — Orkla ASA
- ORKT — Orangekloud Technology Inc.
- ORLCF — Oracle Commodity Holding Corp.
- ORLY — O'Reilly Automotive, Inc.
- ORMNF — Orex Minerals Inc.
- ORMP — Oramed Pharmaceuticals Inc.
- ORMTQ — Ormet Corporation
- ORN — Orion Group Holdings, Inc.
- ORN.AX — Orion Minerals Limited
- OROVF — Orient Overseas (International) Limited
- OROVY — Orient Overseas (International) Limited
- OROXF — Orosur Mining Inc.
- ORP.AX — Orpheus Uranium Limited
- ORPB — Oregon Pacific Bancorp
- ORPEF — Orpea S.A.
- ORPOF — OSE Immunotherapeutics S.A.
- ORR — Militia Long/Short Equity ETF
- ORRAF — Orora Limited
- ORRCF — Oroco Resource Corp.
- ORRF — Orrstown Financial Services, Inc.
- ORRYY — Orora Limited
- ORS.V — Orestone Mining Corp.
- ORSX — Orsus Xelent Technologies Inc.
- ORV.TO — Orvana Minerals Corp.
- ORVMF — Orvana Minerals Corp.
- ORWHF — Oriental Watch Holdings Limited
- ORXCF — ORIX Corporation
- ORXGF — Orca Energy Group Inc.
- ORXJF — ORIX JREIT Inc.
- ORXOF — Orexo AB (publ)
- ORXOY — Orexo AB (publ)
- ORYZF — Oryzon Genomics S.A.
- ORZCF — Orezone Gold Corporation
- OSAGF — OSRAM Licht AG
- OSBC — Old Second Bancorp, Inc.
- OSBK — Oconee Financial Corporation
- OSCI — Osceola Gold, Inc.
- OSCR — Oscar Health, Inc.
- OSCUF — Japan Exchange Group, Inc.
- OSCV — Opus Small Cap Value Plus ETF
- OSCX — Defiance Daily Target 2X Long OSCR ETF
- OSEA — Harbor International Compounders ETF (OSEA)
- OSG — Octave Specialty Group, Inc.
- OSGCF — OSG Corporation
- OSGSF — Osaka Gas Co., Ltd.
- OSGSY — Osaka Gas Co., Ltd.
- OSHDF — Oshidori International Holdings Limited
- OSIS — OSI Systems, Inc.
- OSK — Oshkosh Corporation
- OSKXF — Osaka Steel Co., Ltd.
- OSL.AX — OncoSil Medical Ltd
- OSM.AX — Osmond Resources Limited
- OSOPF — Osotspa Public Company Limited
- OSPN — OneSpan Inc.
- OSPRU — Osprey Acquisition Corp. III
- OSRHW — OSR Holdings, Inc.
- OSS — One Stop Systems, Inc.
- OSSFF — Embla Medical hf.
- OSSUY — Embla Medical hf.
- OST — Ostin Technology Group Co., Ltd.
- OSTIY — Österreichische Post AG
- OSTTF — OSAKA Titanium technologies Co.,Ltd.
- OSTX — OS Therapies Incorporated
- OSUKF — Otsuka Corporation
- OSUR — OraSure Technologies, Inc.
- OSW — OneSpaWorld Holdings Limited
- OSX.AX — Osteopore Limited
- OTAI — Starlink Ai Acquisition Corp.
- OTC.V — Ocumetics Technology Corp.
- OTCFF — Ocumetics Technology Corp.
- OTCM — OTC Markets Group Inc.
- OTEX — Open Text Corporation
- OTEX.TO — Open Text Corporation
- OTF — Blue Owl Technology Finance Corp.
- OTFT — Out Front Companies Inc.
- OTGA — OTG Acquisition Corp. I Class A Ordinary Share
- OTGAU — OTG Acquisition Corp. I Unit
- OTGAW — OTG Acquisition Corp. I Warrants
- OTGL — OTG Latin America ETF
- OTGLF — CD Projekt S.A.
- OTGLY — CD Projekt S.A.
- OTIS — Otis Worldwide Corporation
- OTLC — Oncotelic Therapeutics, Inc.
- OTLK — Outlook Therapeutics, Inc.
- OTLY — Oatly Group AB
- OTMN — The O.T. Mining Corporation
- OTOW — O2 Secure Wireless, Inc.
