Slippage in Trading: What It Is, Why It Happens and How to Reduce It

You click buy at $50.00 and the fill comes back at $50.12. That 12 cents is slippage. It looks small on one trade, but across hundreds of trades it can turn a profitable system into a losing one. Here is why it happens and what you can do about it.

What slippage is

Slippage is the gap between the expected price and the executed price. It can be:

• Negative: you buy higher or sell lower than expected. This is the one that costs money.
• Positive: the order fills at a better price than expected. It happens, but less often.

Why it happens

1. Fast markets. Price moves between the moment you decide and the moment the order reaches the exchange. News releases and the market open are the usual triggers.
2. Low liquidity. There may not be enough orders at your price to fill the whole size, so the rest fills at the next price levels. See liquidity in trading.
3. Large order size. A bigger order walks through more price levels in the order book.
4. Order type. A market order accepts any price. A stop order turns into a market order when triggered, and can fill well beyond the stop price in a gap or fast move.
5. Gaps. Between sessions or across a weekend, price can open far from where it closed, and your stop fills at the open price.

A worked example

You trade a stock with a $50 entry and a $48 stop, risking 100 shares, so your planned risk is $200.

• Entry slips 5 cents to $50.05.
• Price drops, your stop triggers at $48.00, but the market is moving fast and the order fills at $47.85.
• Actual loss: ($50.05 − $47.85) × 100 = $220, not $200. That is 10% more than planned.

Now suppose you make 200 trades a year with an average of $15 lost to slippage on each. That is $3,000 a year, which can exceed the profit of a modest strategy. It is part of the true cost of trading, alongside commissions and the spread.

How to reduce slippage

• Use limit orders when you can. A limit order will not fill at a worse price than the one you set. The trade-off is that it may not fill at all.
• Trade liquid instruments. Large stocks, major forex pairs and index futures slip far less than small caps and thin coins.
• Avoid trading into news. Spreads widen and prices jump around scheduled releases. See the economic calendar guide.
• Trade during peak hours for your market, rather than pre-market or after-hours. See pre-market trading.
• Reduce size in thin markets. Splitting a large order into smaller pieces limits its impact on the price.
• Understand your stop type. A stop-limit order caps the fill price but may not fill. See stop-limit vs stop-loss.
• Allow for it in your plan. Add an estimate of slippage to your costs when you test a strategy, and compare real fills with expected ones in your journal. See what is backtesting and how to journal your trades.

Slippage in crypto and forex

In forex, slippage is small on major pairs in normal conditions and large around central bank decisions or jobs data. In crypto, depth varies a lot by exchange and coin, and slippage on small coins can be severe. On decentralised exchanges, you usually set a slippage tolerance (a percentage). A tolerance that is too low makes the trade fail, and too high lets bots trade against you at bad prices.

FAQ

Educational content, not financial advice. Trading involves substantial risk of loss.