Trading glossaryReviewed 16 July 2026
Definition
Lot size is a standardized or platform-defined transaction quantity used to express how many units of an instrument a trade controls.
In market context
In foreign exchange, market conventions often describe standard, mini, or micro lots, while other products use contract or share quantities. Lot size combines with price movement and leverage to determine notional exposure and the cash value of a pip. Users should rely on the platform’s displayed units and contract specification because the same label can represent different quantities across instruments.
Source
Use the primary source for fuller regulatory or market context.