The usual minimum price change of 0.0001 in many major forex pairs is called a pip.
“Pip” is commonly expanded as “percentage in point” and denotes a conventional unit of exchange-rate movement. For a pair such as EUR/USD, a move from 1.2500 to 1.2501 is one pip; a move to 1.2510 is ten pips. The term gives traders a compact way to discuss movements, gains, losses and risk.
The rule is not identical for every currency. Pairs involving the Japanese yen traditionally count one pip at the second decimal place, so a move from 150.20 to 150.21 is one pip. Electronic platforms may also display fractional pips, often called pipettes, by adding another decimal digit.
A pip is related to, but not always identical with, a tick. Pip describes the conventional forex movement unit, while tick size means the smallest permitted price increment on a particular market or platform. Spread, meanwhile, is the gap between bid and ask prices.