Lot
A lot is a quantity of the asset. In MetaTrader 5, one lot is the symbol's contract size.
Explanation
MetaTrader 5's help says the contract size is the number of units of the commodity, currency or asset in one lot. Volume is then a number of lots. The forex margin example uses a contract size of 100,000 for EURUSD and a volume of one lot. That figure is the example's assumption. The contract size on a live symbol is whatever the broker's specification says.
This page explains published terms for education and reference. It is not financial, investment, tax, or trading advice, and it does not recommend a firm, product, or strategy.
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Sources and last check
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