| | OKEY.L | O'Key Group S.A. GDR | LSE |
| | ORLY | O'Reilly Automotive, Inc. | NASD |
| | OIIM | O2Micro Intl Ltd. | NASD |
| | OIII.V | O3 Mining Inc. | TSXV |
| | OSH | Oak Street Health, Inc. | NYSE |
| | OVLY | Oak Valley Bancorp | NASD |
| | OARMX | Oakmark | USMF |
| | OARBX | Oakmark Equity & Income II | USMF |
| | OAKBX | Oakmark Equity and Income I | USMF |
| | OAKMX | Oakmark Fund Cl I | USMF |
| | OARGX | Oakmark Global | USMF |
| | OAKGX | Oakmark Global Fund Class I; a series of Harris Associates Investment Trust | USMF |
| | OAKWX | Oakmark Global Select I | USMF |
| | OARIX | Oakmark International | USMF |
| | OAKIX | Oakmark International I | USMF |
| | OAKEX | Oakmark International Small Cap I | USMF |
| | OARLX | Oakmark Select | USMF |
| | OAKLX | Oakmark Select Fund (The) Cl I | USMF |
| | OAK/PA | Oaktree Capital Group LLC | NYSE |
| | OAK/PB | Oaktree Capital Group LLC | NYSE |
| | OCSL | Oaktree Specialty Lending Corporation | NASD |
| | OCSI | Oaktree Strategic Income Corporation | NASD |
| | OGZD.L | OAO Gazprom ADR | LSE |
| | LKOD.L | OAO Lukoil ADR | LSE |
| | NVTK.L | OAO Novatek GDR | LSE |
| | ATAD.L | OAO Tatneft ADR | LSE |
| | TMKS.L | OAO TMK GDR | LSE |
| | OMP | Oasis Midstream Partners LP | NASD |
| | OAS | Oasis Petroleum Inc. | NASD |
| | OASMY | Oasmia Pharmaceutical AB | PINK |
| | OBLN | Obalon Therapeutics, Inc. | NASD |
| | OBEROIRLTY.IN | Oberoi Realty Ltd. | NSE |
| | OBCHX | Oberweis China Opportunities | USMF |
| | OBEGX | Oberweis Emerging Growth Fund Portfolio Of Oberweis Micro Cap | USMF |
| | OBIOX | Oberweis International Opportunities Fund | USMF |
| | OBMCX | Oberweis Micro Cap Portfolio | USMF |
| | OBSOX | Oberweis Small-Cap Opportunities Fund | USMF |
| | OBLG | Oblong, Inc | AMEX |
| | OBSV | ObsEva SA | NASD |
| | OBE.TO | Obsidian Energy Ltd. | TSE |
| | OBELF | Obsidian Energy Ltd. | PINK |
| | OCDO.L | Ocado Group | LSE |
| | OCDGF | Ocado Group plc | PINK |
| | OXY | Occidental Petroleum Corp. | NYSE |
| | OBCI | Ocean Bio-Chem, Inc. | NASD |
| | OPTT | Ocean Power Technologies Inc. | NASD |
| | OCANF | OceanaGold Corp. | PINK |
| | OGC.TO | OceanaGold Corp. | TSE |
| | OII | Oceaneering Intl, Inc. | NYSE |
| | OCFC | OceanFirst Financial Corp. | NASD |
| | FEO.V | Oceanic Iron Ore Corp. | TSXV |
| | SCU | Och-Ziff Capital Management Group LLC | NYSE |
| | OISL.IN | OCL Iron & Steel Ltd | NSE |
| | OFED | Oconee Federal Financial Corp. | NASD |
| | OSL/UN.TO | OCP Senior Credit Fund | TSE |
| | OCGN | Ocugen Inc. | NASD |
| | OCUL | Ocular Therapeutix Inc. | NASD |
| | OVT.V | Oculus VisionTech Inc. | TSXV |
| | OVTZ | Oculus Visiontech, Inc. | PINK |
| | OCN | Ocwen Financial Corp. | NYSE |
| | ODT | Odonate Therapeutics, Inc. | NASD |
| | ODYY | Odyssey Group Intl Inc. | PINK |
| | OMEX | Odyssey Marine Exploration, Inc. | NASD |
| | !PMOAZOEX | OEX % PMO Above Zero | INDX |
| | !PMORISOEX | OEX % PMO Rising | INDX |
| | !PMOBUYOEX | OEX % PMO Xover BUY Signals | INDX |
| | !1EMAOEX | OEX 1% EMA of Advance-Decline Ratio | INDX |
| | !10INDROEX | OEX 10% Index (RA) | INDX |
| | !10VLIROEX | OEX 10% Volume Index (RA) | INDX |
| | !5INDROEX | OEX 5% Index (RA) | INDX |
| | !5VINROEX | OEX 5% Volume Index (RA) | INDX |
| | !50EMABOEX | OEX 50% EMA of Advance-Decline Ratio | INDX |
| | !50EMAVOEX | OEX 50% EMA of Advance-Decline Volume Ratio | INDX |
| | !ADLINEOEX | OEX Advance-Decline Line | INDX |
| | !ADVOLOEX | OEX Advance-Decline Volume (Net A-D Vol) | INDX |
| | !CUMVOLOEX | OEX Advance-Decline Volume Line | INDX |
| | !ADVRATOEX | OEX Advance-Decline Volume Ratio | INDX |
| | !ADVOEX | OEX Advances | INDX |
| | !NETADOEX | OEX Advances Minus Declines (Net A-D) | INDX |
| | !ADRATOEX | OEX Daily Advance-Decline Ratio | INDX |
| | !DECLOEX | OEX Declines | INDX |
| | !DVOLOEX | OEX DOWN Volume | INDX |
| | !ITBMRAOEX | OEX IT Breadth Momentum Osc (ITBM) | INDX |
| | !ITVMOEX | OEX IT Volume Momentum Osc (ITVM) | INDX |
| | !MCOSIROEX | OEX McClellan Osc | INDX |
| | !MCSUMROEX | OEX McClellan Summation Index | INDX |
| | !VMCOSIOEX | OEX McClellan Volume Osc | INDX |
| | !NEWHIOEX | OEX New Highs | INDX |
| | !NEWLOOEX | OEX New Lows | INDX |
| | !GT20OEX | OEX Stocks Above 20-EMA | INDX |
| | !GT200OEX | OEX Stocks Above 200-EMA | INDX |
| | !GT50OEX | OEX Stocks Above 50-EMA | INDX |
| | !STOBOEX | OEX Swenlin TradOsc-Breadth (STO-B) | INDX |
| | !STOVOEX | OEX Swenlin TradOsc-Volume (STO-V) | INDX |
| | !TOVOLOEX | OEX Total Volume | INDX |
| | !UVOLOEX | OEX UP Volume | INDX |
| | !VMCSUMOEX | OEX Volume McClellan Summation Index | INDX |
| | OPI | Office Properties Income Trust | NASD |
| | OPINI | Office Properties Income Trust | NASD |
| | OFS | OFS Capital Corp. | NASD |
| | OCCI | OFS Credit Co., Inc. | NASD |
| | OGE | OGE Energy Corp. | NYSE |
| | OVBC | Ohio Valley Banc Corp. | NASD |
| | NBSE | Ohr Pharmaceutical, Inc. | NASD |
| | OIBR/C | Oi S.A. ADS | NYSE |
| | OIBRQ | Oi S.A. ADS | PINK |
| | ONGC.IN | Oil & Natural Gas Corp. Ltd. | NSE |
| | OILCOUNTUB.IN | Oil Country Tubular Ltd. | NSE |
| | ODC | Oil Dri Corp. Of America | NYSE |
| | $XOI | Oil Index - NYSE Arca | INDX |
| | OIL.IN | Oil India Ltd. | NSE |
| | OISHY | Oil Search Limited | PINK |
| | $OSX | Oil Services Index - Philadelphia | INDX |
| | OIS | Oil States Intl | NYSE |
| | OEX.L | Oilex Ltd | LSE |
| | ROSN.L | OJSC Rosneft Oil Co. | LSE |
| | OKTA | Okta, Inc. | NASD |
| | ODFL | Old Dominion Freight Line, Inc. | NASD |
| | ONB | Old National Bancorp | NASD |
| | OPOF | Old Point Financial Corp. | NASD |
| | ORI | Old Republic Intl Corp. | NYSE |
| | OSBC | Old Second Bancorp, Inc. | NASD |
| | OLECTRA.IN | Olectra Greentech Limited | NSE |
| | OLN | Olin Corp. | NYSE |
| | OLVRF | Olivut Resources Ltd. | PINK |
| | OLLI | Ollie's Bargain Outlet Holdings Inc. | NASD |
| | OFAFX | Olstein Financial Alert Adv | USMF |
| | OFALX | Olstein Financial Alert Fund | USMF |
| | OFSCX | Olstein Strategic Opportunities Fund | USMF |
| | ZEUS | Olympic Steel, Inc. | NASD |
| | OCPNY | Olympus Corp. | PINK |
| | OMMETALS.IN | OM Metals Infraprojects Ltd. | NSE |
| | OMAXAUTO.IN | Omax Autos Limited | NSE |
| | OMAXE.IN | Omaxe Ltd. | NSE |
| | OFLX | Omega Flex Inc | NASD |
| | OHI | Omega Healthcare Invs, Inc. | NYSE |
| | OMER | Omeros Corp. | NASD |
| | OMID | Omid Hldgs Inc | PINK |
| | OMM.V | Omineca Mining and Metals Ltd. | TSXV |
| | OMKARCHEM.IN | Omkar Speciality Chemicals Ltd. | NSE |
| | OMHE | Omni Health Inc | PINK |
| | OML.V | Omni-Lite Industries Canada, Inc. | TSXV |
| | OMCL | Omnicell Inc. | NASD |
| | OMC | Omnicom Group, Inc. | NYSE |
| | OMTK | OmniTek Engineering Corp. | PINK |
| | OMRNY | Omron Corp | PINK |
| | $OMXC20CP | OMX Copenhagen 20 CAP Index | OMX |
| | $OMXC20 | OMX Copenhagen 20 Index | OMX |
| | $HEX25 | OMX Helsinki 25 Index | INDX |
| | $OMXN40 | OMX Nordic 40 Index | OMX |
| | $OMXS30 | OMX Stockholm 30 Index | OMX |
| | ON | ON Semiconductor Corp. | NASD |
| | OTB.L | On The Beach Group PLC | LSE |
| | OTIVF | On Track Innovations Ltd. | PINK |
| | OBMP | OncBioMune Pharmaceuticals, Inc. | PINK |
| | OCX | OncoCyte Corp. | AMEX |
| | ONPH | Oncology Pharma Inc. | PINK |
| | ONC.TO | Oncolytics Biotech, Inc. | TSE |
| | ONCY | Oncolytics Biotech, Inc. | NASD |
| | ONTX | Onconova Therapeutics, Inc. | NASD |
| | ONCS | OncoSec Medical Inc. | NASD |
| | ONCT | Oncternal Therapeutics, Inc. | NASD |
| | ONDK | OnDeck Capital Inc. | NYSE |
| | $ONE | One | INDX |
| | OGS | ONE Gas Inc. | NYSE |
| | PGBOX | One Group Bond | USMF |
| | OBOCX | One Group Bond Fund | USMF |
| | ODMCX | One Group Diversified Mid Cap Fund | USMF |
| | PECAX | One Group Diversified Mid Cap Fund - Class A | USMF |
| | WOOPX | One Group Diversified Mid Cap Fund Class I | USMF |
| | OIEIX | One Group Equity Income Fund Class A | USMF |
| | OGEAX | One Group Equity Index Fund A | USMF |
| | OEICX | One Group Equity Index Fund Class C | USMF |
| | HLEIX | One Group Equity Index Portfolio Class I | USMF |
| | OGGAX | One Group Government Bond Fund | USMF |
| | OGHCX | One Group High Yield Bond Fund | USMF |
| | OHYAX | One Group High Yield Bond Fund | USMF |
| | STKS | ONE Group Hospitality, Inc. | NASD |
| | HLIPX | One Group Income Bond Class I | USMF |
| | OBDCX | One Group Income Bond Fund | USMF |
| | OEIAX | One Group International Equity Index Fund | USMF |
| | OGIAX | One Group Investor Balanced | USMF |
| | OCGCX | One Group Investor Conservative Growth Fund | USMF |
| | OICAX | One Group Investor Conservative Growth Fund | USMF |
| | ONCFX | One Group Investor Conservative Growth Fund Class I | USMF |
| | ONGAX | One Group Investor Growth | USMF |
| | ONGFX | One Group Investor Growth & Income | USMF |
| | ONECX | One Group Investor Growth & Income Fund | USMF |
| | ONGIX | One Group Investor Growth & Income Fund - Class A | USMF |
| | SEEGX | One Group Large Cap Growth | USMF |
| | OLGAX | One Group Large Cap Growth Fund - Class A | USMF |
| | OLGCX | One Group Large Cap Growth Fund Class C | USMF |
| | OLVAX | One Group Large Cap Value Fund | USMF |
| | PGMIX | One Group Market Expansion Index | USMF |
| | OMEAX | One Group Market Expansion Index Fund | USMF |
| | OMECX | One Group Market Expansion Index Fund Class C | USMF |
| | OSGIX | One Group Mid Cap Growth Fund - Class A | USMF |
| | OMGCX | One Group Mid Cap Growth Fund Class C | USMF |
| | HLGEX | One Group Mid Cap Growth Fund Class I | USMF |
| | OTBAX | One Group Municipal Income Fund | USMF |
| | OSTAX | One Group Short Term Municipal Bond Fund | USMF |
| | OSTCX | One Group Short-Term | USMF |
| | HLLVX | One Group Short-Term Bond Fund | USMF |
| | OGLVX | One Group Short-Term Bond Fund | USMF |
| | STMCX | One Group Short-term Municipal Bond Fund | USMF |
| | OSGCX | One Group Small Cap Growth Fund Class C | USMF |
| | OGGFX | One Group Small Cap Growth Fund Class I | USMF |
| | PSOAX | One Group Small Cap Value | USMF |
| | PSOPX | One Group Small Cap Value | USMF |
| | OSVCX | One Group Small Cap Value Fund | USMF |
| | PRBIX | One Group Tax Free Bond Fund | USMF |
| | OGUCX | One Group Ultra Short-Term | USMF |
| | HLGFX | One Group Ultra Short-Term Bond Fund | USMF |
| | ONUAX | One Group Ultra Short-Term Bond Fund | USMF |
| | OLP | One Liberty Properties, Inc. | NYSE |
| | ONEPOINT.IN | One Point One Solutions Ltd | NSE |
| | KOSK | One Step Vending Corp | PINK |
| | OSS | One Stop Systems Inc. | NASD |
| | OWLI.CA | One World Lithium Inc. | CSE |
| | OCFT | OneConnect Financial Technology Co. Ltd. | NYSE |
| | ONELIFECAP.IN | Onelife Capital Advisors Ltd. | NSE |
| | OMF | OneMain Holdings, Inc. | NYSE |
| | OKE | Oneok, Inc. | NYSE |
| | OSB.L | Onesavings Bank | LSE |
| | ONE | OneSmart International Education Group Limited | NYSE |
| | OSS.V | OneSoft Solutions Inc. | TSXV |
| | OSPN | OneSpan Inc. | NASD |
| | OSW | OneSpaWorld Holdings Ltd. | NASD |
| | ONEW | OneWater Marine | NASD |
| | ONEX.TO | ONEX Corp. | TSE |
| | ONMOBILE.IN | OnMobile Global Ltd. | NSE |
| | ONTO | Onto Innovation Inc | NYSE |
| | OTRFX | OnTrack Core Fund | USMF |
| | OTRK | Ontrak, Inc. | NASD |
| | ONWARDTEC.IN | Onward Technologies Ltd. | NSE |
| | OOMA | Ooma, Inc. | NYSE |