What a lot actually is
In forex, a "lot" is a standardised unit of position size. One standard lot is 100,000 units of the base currency. A mini lot is 10,000 units (0.1 lots), and a micro lot is 1,000 units (0.01 lots). The lot size you choose determines how much money each pip of movement is worth.
This is where many beginners quietly destroy their accounts. They open a full standard lot without realising how large it is, then watch a normal price wobble produce swings far bigger than they can stomach. Understanding lot size is understanding how much you are truly risking.
Pip value by lot size
On a pair like EUR/USD, one pip is roughly $10 per standard lot, $1 per mini lot, and $0.10 per micro lot. So if the price moves 50 pips against you on a standard lot, that is a $500 loss. The same move on a micro lot is a $5 loss.
Put concretely: on a $1,000 account, trading a standard lot means a routine 30-pip move is a $300 swing — 30% of your balance in one ordinary session. Trading a micro lot instead makes that same move a $3 swing. The market is identical; only your exposure changed.
Choosing a size that survives
Position size should be decided by how much you are willing to lose on a single trade, not by how much you would like to make. A common approach is risking a small fixed percentage per trade and then working backwards to the lot size that matches it, given your stop-loss distance.
Start smaller than feels exciting. Micro lots let you learn the mechanics of trading with real money at stake but without account-ending losses. There is no prize for using large lots early, and plenty of accounts have been wiped out chasing one.