A situation where a broker or exchange introduces bias in slippage, where negative slippage (worse fills) occurs more frequently than positive slippage (better fills), disadvantaging the trader. This practice is considered unethical and may violate regulatory standards, as fair execution policies should allow both positive and negative slippage to occur naturally. Traders should monitor their fill quality and consider switching brokers if asymmetric slippage is detected.
Example
“After analyzing my trade fills, I noticed asymmetric slippage — I was consistently getting worse fills on entries while never receiving positive slippage.”