Lot Size Definition and Requirement
Lot Size refers to the minimum trading and position unit of a contract.
Order Quantity and Position Sizes must be multiples of the contract's Lot Size; orders not meeting this requirement will be rejected. Lot Sizes for each contract can be found on the Contract's Specification page.
Lot Size Examples
XBTUSD's Lot Size is 100. Valid order quantities include 100, 200, 500, or 1000 contracts. Quantities like 1, 5, 10, 35, 125, or 250 contracts would be rejected. Similarly, permissible position sizes are 100, 200, 500, or 1000 contracts, but not 1, 5, 10, 35, 125, or 250 contracts.
Handling Changes in Lot Size
Occasionally, there may be an adjustment to a contract's Lot Size. In such cases, orders and positions may be rounded down to the nearest Lot Size, leading to the "odd lot" portion of the position being closed out.