Off-Balance SheetOfferOfficial Settlements AccountOffsetOffsetting a hedgeOffsetting a long optionOff-ShoreOld LadyOne Cancels Other Order (O.C.O. Order)Open interestOpen Market OperationsOpen orderOpen outcryOpen/Open PositionOpen OrderOpeningOpening rangeOptionsOption assignmentOption buyerOption ClassOption sellerOption SeriesOrderOrder-cancels-other (OCO)Out-of-the-MoneyOutright DealOutright ForwardOutright RateOut-tradesOverboughtOverheated (Economy)OvernightOvernight LimitOversoldOver The Counter (OTC)