Slippage occurs when you wish to enter the market at a certain price, but due to the extreme volatility during these events, you actually get filled at a far different price.
Slippage is the difference between the expected fill price and the actual fill price. If the actual fill price is better than the expected fill price, this is referred to as “positive slippage “. If the actual fill price is worse than the price requested, this is known as “negative slippage “.
Traders usually experience negative slippage in highly volatile markets such as during news or economic releases. Therefore, you should be careful when trading the news.