Odd lot - An "odd lot" is a non-standard amount for a transaction.

Offer - An "offer" is the price at which a seller is willing to sell. The best offer is the lowest such price available.

Offset - "Offset" is the closing-out or liquidation of a futures position.

Offshore - "Offshore" is the operations of a financial institution, which although physically located in a country, has little connection with that country's financial systems. In certain countries, a bank is not permitted to do business in the domestic market but only with other foreign banks. This is known as an offshore banking unit.

Overnight limit - An "overnight limit" is the net long or short position in one or more currencies that a dealer can carry over into the next dealing day. Passing the book to other bank dealing rooms in the next trading time zone reduces the need for dealers to maintain these unmonitored exposures.

Overnight - "Overnight" means a deal from today until the next business day.