A record of trades and the details of the trades made over a period of time (usually one trading day). The details of a trade will include such things as the time, price, order size and a specification of whether it was a buy or sell order. The blotter is usually created through a trading software program that records the trades made through a data feed. Taobiz explains Blotter The purpose of a trade blotter is to carefully document the trades so that they can be reviewed and confirmed by the trader or the brokerage firm. The blotter is used in the stock market, foreign exchange market, and the bond market and can be customized based on the needs of the user.