Slippage: What It Means

Slippage happens when the market moves between the moment an order is sent and the moment it is filled. It is most common during news releases and in fast or thin markets.

Slippage can work for or against you, but it matters most for strategies with small targets. A bot aiming for three pips can lose its whole edge to one pip of slippage. Demo accounts usually show none, which is one reason demo results look better than live results.