Common in spot forex trading, lot sizes are the amount of units required to make a trade. Within forex trading, the lot sizes are typically 100, 1,000, 10,000, or 100,000. Recently, non-standard lot sizes (or “odd lots”) have also become available to forex traders. Standard lots are the equivalent of 100,000 units of the base currency in a forex trade.
We don't know everything about the markets. We're just devoted to learners. Taken from those smarter than ourselves, here's how we define Lot Size.