> For the complete documentation index, see [llms.txt](https://docs.imperial.trade/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.imperial.trade/trading/slippage-and-price-protection.md).

# Slippage & Price Protection

**Slippage** is the difference between the price you expect and the price you get. Bigger orders and thinner books mean more slippage.

### Your slippage limit

Every market order, TP/SL and other triggered order carries a slippage limit. Imperial protects it twice:

1. **At the venue.** The hedge order is sent with a worst acceptable price at your limit, so the venue won't fill it beyond that.
2. **On-chain.** The Imperial program refuses any fill worse than your limit, whatever the website or API sent.

If the book can only fill part of your order inside the limit, the rest is cancelled. If nothing fills, the order is rejected and your collateral is returned.

**Price improvement is yours.** If the fill is better than expected, you keep the difference.

### When an order can't trade

| You see                               | Meaning                                                                                                                                          |
| ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Slippage exceeded**                 | The book moved beyond your limit before the order filled. Retry or widen your limit.                                                             |
| **Market closed**                     | The book is too far from the mark price to trade, usually because the underlying TradFi market is closed. Triggered orders stay armed and retry. |
| **Size too large**                    | The order is above the venue's maximum order size. Split it up.                                                                                  |
| **No capacity**                       | Imperial can't take the other side of this order right now. See [Risk Limits](https://docs.imperial.space/trading/risk-limits).                  |
| **Order may still have gone through** | Confirmation from the venue was delayed. Check your positions before retrying. Imperial never sends a duplicate.                                 |