• OBAS
• Optibase Ltd. - Ordinary Shares

• OBCI
• Ocean Bio-Chem, Inc. - Common Stock

• OCCF
• Optical Cable Corporation - Common Stock

• OCCX
• OccuLogix, Inc. - Common Stock

• OCFC
• OceanFirst Financial Corp. - Common Stock

• OCLS
• Oculus Innovative Sciences, Inc. - Common Stock

• OCNF
• OceanFreight Inc. - common stock

• OCNW
• Occam Networks, Inc. - Common Stock

• ODFL
• Old Dominion Freight Line, Inc. - Common Stock

• ODSY
• Odyssey Healthcare, Inc. - Common Stock

• OESX
• Orion Energy Systems, Inc. - Common Stock

• OFIX
• Orthofix International N.V. - Common Stock

• OFLX
• Omega Flex, Inc. - Common Stock

• OFSI
• Omni Financial Services, Inc. - Commmon Stock

• OICO
• O. I. Corporation - Common Stock

• OIIM
• O2Micro International Limited - American Depositary Shares

• OJZST
• SUPERMONTAGE TEST

• OKSB
• Southwest Bancorp, Inc. - Common Stock

• OLBK
• Old Line Bancshares, Inc. - Common Stock

• OLCB
• Ohio Legacy Corporation - Common Stock

• OLGC
• Orthologic Corp. - Common Stock

• OMAB
• Grupo Aeroportuario del Centro Norte S.A.B. de C.V. - ADS

• OMCL
• Omnicell, Inc. - Common Stock

• OMEX
• Odyssey Marine Exploration, Inc. - Common Stock

• OMGI
• Orion Marine Group Inc - Common

• OMNI
• OMNI Energy Services Corp. - Common Stock

• OMPI
• Obagi Medical Products, Inc. - Common Stock

• OMRI
• Omrix Biopharmaceuticals, Inc. - Common Stock

• OMTR
• Omniture, Inc. - Common Stock

• ONAV
• Omega Navigation Enterprises, Inc. - Class A Common Stock

• ONCY
• Oncolytics Biotech, Inc. - Common Shares

• ONEQ
• Fidelity Nasdaq Composite Index Tracking Stock - Fidelity Nasdaq Composite Index Tracking Stock

• ONFC
• Oneida Financial Corp. - Common Stock

• ONNN
• ON Semiconductor Corporation - Common Stock

• ONSM
• Onstream Media Corporation - Common Stock

• ONTY
• Oncothyreon Inc . - Common Shares

• ONVI
• Onvia, Inc. - Common Stock

• ONXX
• ONYX Pharmaceuticals, Inc. - Common Stock

• OPHC
• OptimumBank Holdings, Inc. - Common Stock

• OPLK
• Oplink Communications, Inc. - Common Stock

• OPMR
• Optimal Group, Inc. - Class A Common Stock

• OPNT
• OPNET Technologies Inc. - Common Stock

• OPOF
• Old Point Financial Corporation - Common Stock

• OPTC
• Optelecom-NKF, Inc. - Common Stock

• OPTM
• Optium Corporation - Common Stock

• OPTR
• Optimer Pharmaceuticals, Inc. - Common Stock

• OPTT
• Ocean Power Technologies, Inc. - Common Stock

• OPTV
• OpenTV Corp. - Class A Ordinary Shares

• OPWV
• Openwave Systems Inc - Common Stock

• OPXA
• Opexa Therapeutics, Inc. - Common Stock

• OPXAW
• Opexa Therapeutics, Inc. - Series E Warrant

• OPXT
• Opnext, Inc. - Common Stock

• ORBC
• ORBCOMM Inc. - Common Stock

• ORBK
• Orbotech Ltd. - Ordinary Shares

• ORBT
• Orbit International Corporation - Common Stock

• ORCC
• Online Resources Corporation - Common Stock

• ORCD
• Orchard Enterprises, Inc (The) - Common Stock

• ORCH
• Orchid Cellmark Inc. - Common Stock

• ORCL
• Oracle Corporation - Common Stock

• ORCT
• Orckit Communications, Limited - Ordinary Shares

• OREX
• Orexigen Therapeutics, Inc. - Common Stock

• ORGN
• Origen Financial, Inc. - Common Stock

• ORIT
• Oritani Financial Corp. - Common Stock

• ORLY
• O'Reilly Automotive, Inc. - Common Stock

• ORNG
• Orange 21 Inc. - Common Stock

• ORXE
• Ore Pharmaceuticals Inc - Common Stock

• OSBC
• Old Second Bancorp, Inc. - Common Stock

• OSBCP
• Old Second Bancorp, Inc. - 7.80% Cumulative Trust Preferred Securities

• OSBK
• Osage Bancshares, Inc. - Common Stock

• OSCI
• Oscient Pharmaceuticals Corporation - Common Stock

• OSHC
• Ocean Shore Holding Co. - Common Stock

• OSIP
• OSI Pharmaceuticals Inc. - Common Stock

• OSIR
• Osiris Therapeutics, Inc. - Common Stock

• OSIS
• OSI Systems, Inc. - Common Stock

• OSTE
• Osteotech, Inc. - Common Stock

• OSTK
• Overstock.com, Inc. - Common Stock

• OSUR
• OraSure Technologies, Inc. - Common Stock

• OTEX
• Open Text Corporation - Common Shares

• OTIV
• On Track Innovations Ltd - Ordinary Shares

• OTTR
• Otter Tail Corporation - Common Stock

• OUTD
• Outdoor Channel Holdings, Inc. - Common Stock

• OVBC
• Ohio Valley Banc Corp. - Common Stock

• OVEN
• TurboChef Technologies, Inc. - Common Stock

• OVRL
• Overland Storage, Inc. - Common Stock

• OVTI
• OmniVision Technologies, Inc. - Common Stock

• OXGN
• OXiGENE, Inc. - Common Stock

• OXPS
• optionsXpress Holdings, Inc. - Common Stock, par value $0.0001 per share

• OYOG
• OYO Geospace Corporation - Common Stock

• OZRK
• Bank of the Ozarks - Common Stock