What is Slippage?
Quick answer
Slippage is the difference between the price you expected on a trade and the price it actually filled at. It happens when the market moves between the decision and the execution, and it is larger in fast-moving or thinly traded markets. In copy trading it matters because a copied order can fill at a slightly different price than the leader got, especially on volatile instruments, so slippage protection and conservative sizing help.
Slippage is a normal part of trading that is easy to overlook until it eats into a result. It is the gap between the price you saw when you decided to trade and the price you actually got when the order filled.
How slippage happens
Prices move continuously, so in the moments between placing an order and it executing, the market can shift. If it moves against you, you fill at a worse price than expected; occasionally it moves in your favor. Slippage tends to be larger when the market is moving fast, when an instrument is thinly traded, or when the spread between the bid and ask is wide. Options and volatile stocks are common places to see it.
Why slippage matters in copy trading
When a trade is copied, your order is placed a moment after the leader’s, so your fill can differ from theirs, more so on fast-moving or wide-spread instruments. It does not mean the copy failed; it is the normal cost of execution. Slippage protection can cap how far from the expected price an order is allowed to fill, and conservative sizing limits how much any single slipped fill can matter. RelayTrades applies slippage protection as part of the checks before an order is placed.
Frequently asked questions
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