Fat-finger error

A fat-finger error is a keyboard input error or mouse misclick that occurs from a simple input mistake, causing unwanted secondary behavior. In common parlance, it simply refers to a common typographical error made on a touchscreen or physical keyboard that occurs when the wrong selection is made, or multiple selections are made due to options or keyboard keys being too close together.

In the context of financial markets, a fat finger error is specifically an instance where the details of a buy or sell order are mistakenly inputted by a user.