Why Your Order Doesn't Always Fill at Your Price
Slippage happens when your order executes at a different price than the one you requested — because between the moment you place the order and the moment the broker actually fills it, the market has moved. In a fast-moving or thin market, that gap can be several pips instead of a fraction of one.
This applies to entries, but it matters most on stop losses: a stop loss is a promise to exit at a certain price, not a guarantee. If price is falling fast and there's no buyer sitting exactly at your stop level, your order fills at the next available price — which can be worse than what you planned for.
Positive vs Negative Slippage
Slippage isn't always against you. If price gaps in your favor before your order fills, you get positive slippage — a better price than requested. If it gaps against you, that's negative slippage. Over enough trades the two roughly offset each other in a genuinely fast-executing environment — but negative slippage tends to cluster exactly when it hurts most: during volatile, one-directional moves.
When Slippage Is Worst
- Major news releases — NFP, FOMC, CPI and similar high-impact events can move price 20-50+ pips in seconds, far faster than liquidity can keep up.
- The weekend open — if something happens between Friday's close and Sunday's open, the market can gap straight past your stop loss with no fills in between at all.
- Low-liquidity hours — late in the New York session, before Sydney/Tokyo pick up, spreads widen and fewer orders sit at any given price.
- Thinly-traded pairs — exotics especially, where there simply isn't a deep queue of orders near the current price.
How to Reduce Your Exposure to It
- Avoid opening trades right before major news — this is exactly why our own signal engine skips issuing new signals within 4 hours of a high-impact release for a pair's related currencies.
- Be extra cautious going into the weekend — a position left open Friday afternoon carries full gap risk over two closed days.
- Trade liquid pairs — majors and clean minors have far tighter, more consistent fills than exotics.
- Choose a broker with fast, reliable execution — this is a real, measurable difference between brokers, not marketing noise. See our broker checklist for what to actually look for.