Also known as:Price Execution Difference, Execution Slippage
What is Slippage?
Slippage is the difference between the price a trader expected on an order and the price at which it actually executes. It appears most during high volatility — such as news releases — and in thin, low-liquidity conditions, when the requested price is no longer available by the time the order reaches the market.
Slippage cuts both ways. Negative slippage fills the trader at a worse price than requested — buying gold at 2001.50 instead of the intended 2000.00. Positive slippage, or price improvement, fills at a better price than requested. Genuine A-book execution (STP/ECN) produces both, because it reflects real, moving liquidity rather than a fixed dealer quote.
Key takeaways
Slippage is the gap between expected and executed price, not a broker 'fee'.
It can be negative (worse fill) or positive (price improvement) — both are normal in live markets.
Market and stop orders are exposed; limit orders avoid negative slippage but may not fill.
Chronic negative slippage drives high-volume client churn faster than almost anything.
Never claim a broker has 'zero slippage' — in true market execution it is unavoidable.
The mechanism is straightforward. Between the moment a trader clicks and the moment the order reaches a liquidity provider, price can move and the top-of-book quantity can be consumed. Market orders and stop orders are especially exposed, because they demand a fill at the best available price rather than a specific one. Limit orders avoid negative slippage but risk not filling at all.
For traders, slippage is a real and unavoidable cost of doing business in a live market. For brokers and partners, a reputation for chronic negative slippage is corrosive: it is one of the fastest ways to lose high-volume clients, so demonstrable low-slippage execution becomes a genuine selling point.
How it works
When a market or stop order is sent, the broker or ECN fills it at the best price currently available. If price has moved or the quoted size has been consumed in the milliseconds since the click, the fill lands away from the expected level — that gap is the slippage. During calm, liquid conditions the gap is usually negligible; during an NFP spike or a thin overnight session it can be many pips.
Execution model shapes what the trader experiences. In A-book STP/ECN routing, slippage is symmetric — both positive and negative fills occur as real liquidity moves. Some B-book or dealing-desk setups may apply asymmetric slippage, passing on negative fills while capping positive ones, which regulators and sophisticated traders scrutinize closely.
Why it matters for partnership: Severe negative slippage is a top reason high-volume clients abandon a broker. If your recommended broker is known for it, you face heavy churn and brand damage — while promoting a broker's low-slippage or price-improvement record is a powerful retention and trust tool.
A client clicks an IB's link to trade the NFP release and tries to buy gold at 2000.00. Volatility fills the order at 2001.50 — 1.50 of negative slippage, or $150 on a standard lot. If this happens repeatedly, the client blames the IB's broker recommendation and withdraws, taking their rebate volume with them.
Negative vs positive slippage
Aspect
Negative slippage
Positive slippage
Fill price
Worse than requested
Better than requested (price improvement)
Trader impact
Higher cost / smaller profit
Lower cost / larger profit
Typical cause
Fast move against the order
Fast move in the order's favor
Marketing angle
Damages trust if chronic
Builds trust when highlighted
Pro Tip
Educate your audience that slippage can be positive — highlighting a broker that routinely delivers price improvement builds far more trust than pretending slippage never happens.
Common Pitfalls
Telling clients a broker 'never has slippage': in genuine A-book (STP/ECN) execution slippage is an unavoidable reality of moving liquidity, so the claim collapses the first time a client sees a bad fill.
FAQ
Is slippage always bad for the trader?
No. Slippage can be negative (a worse fill) or positive (price improvement). In true market execution both occur, so it is not inherently a loss.
Can a broker eliminate slippage entirely?
Not in genuine A-book execution. Slippage reflects real, moving liquidity, so any claim of 'zero slippage' should be treated with suspicion.
Why is slippage worse during news events?
Volatility surges and liquidity providers thin their quotes, so price can move sharply in the milliseconds between the click and the fill, widening the gap.
How can traders reduce slippage?
Use limit orders where possible, trade during liquid sessions, choose a low-latency broker or VPS, and avoid entering market orders in the first seconds of a major release.
What is asymmetric slippage?
It is when a broker passes on negative slippage to the client but caps or withholds positive slippage. Regulators and sophisticated traders view the practice critically.
Why should an IB care about slippage?
A broker with chronic negative slippage drives high-volume clients away, cutting your rebate stream. Promoting demonstrable execution quality is a retention tool.
How to evaluate a broker's copy-trading architecture, execution quality, and compliance posture so your followers' results actually match your strategy.
For a signal seller, the broker is the product. Here is how to choose one whose execution, regulation, and copy infrastructure keep your track record and …
A due-diligence guide to broker latency, slippage, and order-routing models for signal and copy-trading providers whose followers' results depend on execution quality they don't control.
