Odd Lot Differential is an additional fee that may be charged to an investor for the handling of odd lot transactions. (Usually waived).
Applying "Odd Lot Differential" to Securities Exams:
Odd Lot Differential may be charged by a broker dealer to offset the additional expenses incurred by handling odd lots. Buying or selling an odd lot may cause a firm additional handling or execution charges. All quotes displayed in the market place are for round lots. Executing a purchase order for an odd lot may require the buyer to pay a little higher price or may cause the seller to accept a slightly lower price as a result.