A micro lot is one-tenth the size of a regular lot, which is 100,000 units (or 10,000 units) in size. One pip of a currency pair based on U.S. dollars is equivalent to $1.00 when trading a micro lot, but one pip is equal to $10.00 when trading a regular lot. In forex mini accounts, which can be opened with a variety of forex broker dealers and used to trade currency pairs, micro lots are the most common lot size.