odd-lot differential

odd-lot differential

The extra markup on odd-lot purchases and markdown on odd-lot sales to compensate the brokerage firm or specialist for dealing in less than round-lot transactions. The differential usually does not apply to odd-lot executions on market opening or to odd lots submitted with round-lot orders for the same security (that is, 260 shares). Also called differential. See also basis price, with or without (WOW).