Lot

What it means

Trading platforms express trade size in lots, and each instrument's contract size says how many units one lot contains. MetaTrader 5's documentation defines contract size as the number of units of the commodity, currency or financial asset in one lot¹, and works its margin examples on one lot of EUR/USD with a contract size of 100,000². A 0.1-lot trade — a mini lot — is therefore 10,000 units, and a 0.01-lot trade — a micro lot — is 1,000.

Metals, indices and other instruments have their own contract sizes, set per instrument by each broker. The contract specification in the trading platform is the authority for any one instrument, not a general rule.

Example

An illustrative trade: a client buys 0.5 lots of EUR/USD, which is 50,000 euros. On a rebate plan, that trade earns the IB half the per-lot rate.

Why it matters to an IB

The lot is the unit an IB's pay is counted in. Rebates are quoted per lot, CPA conditions set minimum lots, and volume tiers are thresholds in lots — so an IB forecasting income is really forecasting lots, instrument group by instrument group.