A lot is the standardized unit used to measure position size in trading, particularly in the foreign exchange market. One standard lot corresponds to 100,000 units of the base currency.
In addition, there are mini lots (10,000 units), micro lots (1,000 units), and nano lots (100 units). The chosen lot size significantly determines how strongly price movements affect a trading account.
For example, in EUR/USD, one pip movement in a standard lot typically equals a profit or loss of around 10 US dollars.
In risk management, selecting the appropriate lot size is a crucial step that should consider account size, risk tolerance, and the distance to the stop-loss level. Many brokers today offer flexible lot sizing, allowing meaningful position management even with smaller capital.
