Contract size is not the same everywhere

[Shadow Trader]

A standard lot in forex is 100,000 units of the base currency. Most brokers follow that convention for currency pairs. For other symbols, metals, indices, crypto, the contract size varies.

Even in currencies, some brokers offer mini or micro lot definitions, where 1 lot equals 10,000 or 1,000 units. The platform's lot field then means something different.

A scalper moving from one broker to another, and entering "1.0" for volume out of habit, can end up with a position ten times larger or smaller than intended. The risk is obvious when the position is bigger. When it's smaller, the commission structure might make the trade unprofitable.

The same confusion applies to pip value. A pip on a 100,000 unit EURUSD position is 10 dollars. On a 10,000 unit position, 1 dollar. A strategy sized by lots needs conversion each time.

The safe habit is to read the contract size in the symbol specification and calculate the notional and pip value for the actual order. Position size calculators help, as long as they use the broker's real numbers.

Hardly glamorous, but the mistake is among the most expensive for traders who switch platforms.

Has a different lot definition ever produced a surprise at order entry?