| OCCIN | OCCIN | US67111Q4047 | |
| OCFC | OCFC | US6752341080 | |
| OCG | OCG | | |
| OCLTU | OCLTU | | |
| OCS | OCS | | |
| OCSAW | OCSAW | | |
| OCTV | OCTV | | |
| Ocugen, Inc. | OCGN | US67577C1053 | |
| Ocular Therapeutix, Inc. | OCUL | US67576A1007 | |
| ODD | ODD | | |
| ODTE | ODTE | US92255C4096 | |
| ODTX | ODTX | US67613T1043 | |
| Odysight.ai Inc. | ODYS | US81063V2043 | |
| Odyssey Marine Exploration, Inc. | OMEX | US6761182012 | |
| OESX | OESX | US6862752077 | |
| OFAL | OFAL | | |
| OFIX | OFIX | US68752M1080 | |
| OFLX | OFLX | US6820951043 | |
| OFS Capital Corporation | OFS | US67103B1008 | |
| OFS Credit Company, Inc. | OCCI | US67111Q1076 | |
| OGGWZ | OGGWZ | | |
| OGI | OGI | US68617J1007 | |
| OHAC | OHAC | | |
| OHACR | OHACR | | |
| OHACU | OHACU | | |
| OIM | OIM | | |
| OIMAU | OIMAU | | |
| OIMAW | OIMAW | | |
| OIO | OIO | | |
| OIOWW | OIOWW | | |
| OKLL | OKLL | US88636V6781 | |
| Okta, Inc. | OKTA | US6792951054 | |
| OKTG | OKTG | US88340C7920 | |
| OKUR | OKUR | US68277Q1058 | |
| OKYO | OKYO | | |
| OLB | OLB | US67086U4067 | |
| Old Dominion Freight Line | ODFL | US6795801009 | |
| Old National Bancorp | ONBPO | US68003D3035 | |
| Old National Bank | ONB | US6800331075 | |
| Old Second Bancorp, Inc. | OSBC | US6802771005 | |
| OLED | OLED | US91347P1057 | |
| Olenox Industries Inc. | OLOX | US78418A8027 | |
| OLLI | OLLI | US6811161099 | |
| OLMA | OLMA | US68062P1066 | |
| OM | OM | US6901452069 | |
| OMAB | OMAB | US4005011022 | |
| OMDA | OMDA | US68170A1088 | |
| Omeros Corporation | OMER | US6821431029 | |
| OMH | OMH | | |
| Omnicell, Inc. | OMCL | US68213N1090 | |
| OMSE | OMSE | | |
| On Semiconductor Corporation | ON | US6821891057 | |
| ONCH | ONCH | | |
| ONCHU | ONCHU | | |
| ONCHW | ONCHW | | |
| ONCO | ONCO | US68237Q4010 | |
| ONCY | ONCY | US68237V1035 | |
| Ondas Inc. | ONDS | US68236H2040 | |
| One Stop Systems, Inc. | OSS | US68247W1099 | |
| ONEG | ONEG | | |
| ONEQ | ONEQ | US3159128087 | |
| Onespan Inc. | OSPN | US68287N1000 | |
| ONEW | ONEW | US68280L1017 | |
| Onfolio Holdings Inc. | ONFO | US68277K2078 | |
| ONMD | ONMD | US68270C1036 | |
| ONMDW | ONMDW | US68270C1119 | |
| OP Bancorp | OPBK | US67109R1095 | |
| OPAL | OPAL | US68347P1030 | |
 Opendoor Technologies Inc. | OPEN | US6837121036 | |
| Opera Limited | OPRA | US68373M1071 | |
| Opko Health, Inc. | OPK | US68375N1037 | |
| Oportun Financial Corporation | OPRT | US68376D1046 | |
| OPPJ | OPPJ | US97717W5215 | |
| OPRX | OPRX | US68401U2042 | |
| Optex Systems Holdings, Inc. | OPXS | US68384X2099 | |
| OPTH | OPTH | US68405H3084 | |
| Optical Cable Corporation | OCC | US6838272085 | |
| Optimize Strategy Index ETF | OPTZ | US00777X5389 | |
| Option Care Health, Inc. | OPCH | US68404L2016 | |
| OPTX | OPTX | US87169M1053 | |
| OPTXW | OPTXW | US87169M1137 | |
| Opus Genetics, Inc. | IRD | US67577R1023 | |
| Oramed Pharmaceuticals Inc. | ORMP | US68403P2039 | |
| OraSure Technologies, Inc. | OSUR | US68554V1089 | |
| ORBS | ORBS | US22890A3023 | |
| ORCS | ORCS | US25461H7888 | |
| ORCU | ORCU | US25461H7961 | |
| ORCX | ORCX | US88636W1971 | |
| Organogenesis Holdings Inc. | ORGO | US68621F1021 | |
| ORIC Pharmaceuticals, Inc. | ORIC | US68622P1093 | |
| ORIO | ORIO | US68627G1040 | |
| ORIQ | ORIQ | | |
| ORIQU | ORIQU | | |
| ORIQW | ORIQW | | |
| ORKA | ORKA | US6876041087 | |
| ORKT | ORKT | | |
| Orrstown Financial Services, Inc. | ORRF | US6873801053 | |
| Orthopediatrics Corp. | KIDS | US68752L1008 | |
| OSCX | OSCX | US88636W1229 | |
| OSI Systems, Inc. | OSIS | US6710441055 | |
