Slippage

Slippage is the difference between the price a trader expected an order to fill at and the price it actually filled at. It shows up most often on market orders and triggered stop orders: by the time the order reaches the exchange and matches against resting liquidity, price may have moved, or the available size at the expected price may already be gone.

Slippage can work in either direction — a fill can be better or worse than expected — but traders generally only notice and name the unfavorable kind. It's a function of the order type and the state of the order book at the moment of execution, not a fixed cost or a broker fee.

Slippage is a normal, unavoidable part of trading any order type that prioritizes speed of execution over price (market orders, triggered stops) — the honest framing is that it comes from real market movement and real order-book depth, not from any single actor's delay. It tends to be largest around fast, thin conditions: economic releases, low-liquidity contract months, or a market gapping through a stop level.

For anyone comparing fills across multiple accounts — including a leader and its followers — slippage is also the reason those fills won't be identical. Each account's order reaches the exchange and matches against the book independently, so two accounts trading the same contract at close to the same time can still get different prices depending on what liquidity is available to each order at the moment it executes.

MimikTrader does not claim identical fills across leader and follower accounts, and does not publish latency numbers. Each follower's order is a separate order that fills at its own market price, based on that account's own execution against the broker at that moment.