A limit order is one of the most basic order types. It allows the trader to specify a price and amount they would like to buy or sell a certain crypto. 

This option is only on Advanced Trade page. 

Example: If the current market price is 1950 and I want to buy lower than that at 1949, then I would place a limit buy order at 1949. If the market reaches 1949 and a seller’s ask matches with my bid, my limit order will be executed at 1949. If the system doesn't find counterpart that matches, the order remains open until it finds one or until the trader cancel it and replace with a different price.