Understanding Slippage: Why Your Fill Is Not the Price You Saw
CryptoRebateHub Editorial Team
Slippage is the gap between the price you saw and your fill, from walking the order book and from delay. How to measure it in bps, estimate it and cap it.
Direct answer: Slippage is the difference between the price you expected when you sent an order and the average price you actually received. A market order fills against resting orders level by level, so once your size exceeds what is resting at the best price, every extra unit fills worse; Binance's own example is a 100 BTC market buy at a 20,000 USD quote filling across 20,000, 20,001 and 20,002 for an average of 20,000.75, or 0.75 USD per BTC of slippage (checked 2026-11-01). It is not shown on the fee line, but it is paid on every taker fill, and on thin pairs it is routinely larger than the trading fee itself.
Where slippage comes from
An order book lists how much is resting at each price. The best ask might hold 0.8 BTC at 60,000, the next 1.5 BTC at 60,001, then 2 BTC at 60,003. A market buy of 0.5 BTC fills entirely at 60,000 with no slippage. A market buy of 3 BTC consumes all three levels and the average is above 60,001, even though the screen showed 60,000 a moment ago. Binance describes this as liquidity slippage: a large order cannot be filled at one price and is matched against progressively worse prices (per Binance's "What Is Slippage?" page, checked 2026-11-01).
The second source is time. Between your click and the matching engine, the quote itself can move. Binance's volatility example has the bid/ask moving from 19,990.50/20,000 to 20,000.50/20,001 before a 100 BTC order fills, costing 1 USD per BTC, or 100 USD on the order (checked 2026-11-01). In a fast market the two sources stack: the book thins out exactly when prices are moving, so the same order size crosses more levels and the levels are further apart.
Slippage is also the main reason a limit order and a market order for the same size can have very different real costs even on an exchange with a flat maker/taker schedule. The order book guide shows how to read the depth that determines it.
Measuring slippage in basis points
Put slippage in the same unit as fees so that the two can be added. Slippage bps = (average fill price − reference price) ÷ reference price x 10,000, with the reference being the best quote (or the mid-price) at the moment you sent the order. Worked book, BTC perpetual, market buy against this ask side:
| Ask level | Price (USDT) | Resting size (BTC) |
|---|---|---|
| 1 | 60,000 | 0.8 |
| 2 | 60,001 | 1.5 |
| 3 | 60,003 | 2.0 |
| 4 | 60,006 | 3.0 |
| Market buy size | Average fill | Slippage vs 60,000 | Slippage in bps | Taker fee at 0.05% (bps) | Total cost (bps) |
|---|---|---|---|---|---|
| 0.5 BTC | 60,000.00 | 0 | 0.0 | 5 | 5.0 |
| 2.0 BTC | 60,000.60 | 0.60 | 0.10 | 5 | 5.10 |
| 4.0 BTC | 60,001.65 | 1.65 | 0.28 | 5 | 5.28 |
| 7.0 BTC | 60,003.39 | 3.39 | 0.56 | 5 | 5.56 |
On a deep BTC book slippage stays below the fee. Replace the resting sizes with a small-cap pair where level one holds 200 USDT of depth and a 5,000 USDT market order can slip by 100 bps or more, twenty times the taker fee. That is why the slippage calculator asks for depth, not just the quote, and why the cost audit checklist treats slippage as a separate line.
The Binance VIP 0 taker rate of 0.05% on USDⓈ-M futures (checked 2026-11-01) is used above; substitute your own rate and exchange from the fee comparison.
How to estimate it before you click
- Open the depth view, not just the ticker. Note the size resting at the best quote and the cumulative size out to a tolerance you accept, such as 0.1% away from the mid.
- Compare your order size to the cumulative depth inside that tolerance. If your order is larger, the market order will cross it.
- Check the spread. Crossing the spread as a taker costs half the spread on its own before any book walking; on illiquid pairs the spread is often the larger of the two costs.
- Look at the time of day and the calendar. Depth is thinner during low-volume hours and immediately around scheduled news, funding settlements and large liquidation cascades.
- For recurring orders, record your realised slippage in bps from the fill history and use the measured distribution, bucketed by order size, in any model; the bot backtest fee and slippage model explains how.
How to keep slippage small
- Use a limit order. A limit order caps the worst price you can receive; it may not fill, but it cannot slip past the limit. The trade-off is laid out in limit vs market orders.
- Set a slippage tolerance where the venue offers one. Binance describes it as the maximum percentage price difference you are willing to accept, typically found on decentralised exchanges and available in its Margin Lite mode (checked 2026-11-01). Hyperliquid's TWAP sends suborders at least 30 seconds apart with a maximum slippage of 3% per suborder (per Hyperliquid's order-type docs, checked 2026-11-01).
- Split the order. Several smaller market orders or a scaled set of limit orders cross fewer levels at a time and let the book refill; Binance's page names TWAP and volume-participation algorithms for the same purpose.
- Trade the liquid venue and pair. The same coin can have ten times the depth on one exchange versus another, and a USDT pair is usually deeper than a cross pair.
- Avoid market orders in the first seconds after a large move or a news print; the book is thinnest when the ticker looks most urgent.
- Watch your stop-loss orders. A stop-market fires as a market order into whatever is on the book at the trigger, so slippage on protective stops is often the largest of the month. The stop-loss guide covers trigger choice.
Mistakes that hide the cost
- Judging an exchange by its fee table alone. A lower taker fee on a thinner book can be a higher all-in cost; the cost audit tool combines the two.
- Modelling slippage as one constant in a backtest. Real slippage is zero on most small fills and large on a few big or badly timed ones; a constant hides the tail.
- Confusing spread with slippage. The spread is paid by every taker fill, slippage is the additional cost of walking beyond the best level; both belong in the cost line.
- Reading the DEX quote as the fill. On automated market makers the quote already includes price impact, and the tolerance setting decides whether the transaction reverts or fills worse.
- Ignoring funding and fees because slippage "was the big one". The total is fees plus spread plus slippage plus funding; optimising one line while another leaks is not a saving.
Related tools and guides
- Slippage calculator
- Trading fee audit: fees, spread, slippage and funding together
- Reading the order book and depth
- How to read an order book without getting fooled
- Including fees and slippage in a bot backtest
- How to actually minimise trading fees
FAQ
Is slippage charged by the exchange?
No. It is not a fee; it is the result of your order matching against worse prices than the one you saw. The exchange only charges the maker or taker fee on each fill. Slippage shows up as a worse average entry or exit price.
Can slippage be positive?
Yes. If the price moves in your favour between order entry and the fill, or a large order arrives on the other side just before yours, the average fill can be better than the quote. For market orders on thin books the expectation is negative.
Do limit orders have zero slippage?
A limit order cannot fill worse than its limit price, so slippage against the limit is zero or positive. The cost moves to opportunity: the order may not fill at all, or may fill only partly.
How much slippage is normal?
On deep pairs such as BTC or ETH perpetuals, small retail orders usually see a fraction of a basis point to a few basis points. On small-cap spot pairs, tens or hundreds of basis points are common for orders that are large relative to the resting depth. Measure your own fills rather than relying on a rule of thumb.
Does a referral rebate offset slippage?
A rebate returns part of the trading fee; it does nothing about slippage. Use the rebate calculator for the fee line and the slippage calculator for the execution line, then add them.
Bottom line
Slippage is the price of taking liquidity that the fee table does not print. It grows with order size relative to resting depth and with the speed of the market, and on thin pairs it can dwarf the taker fee. Measure it in basis points from your own fills, estimate it from the depth before each market order, and cap it with limit orders, tolerance settings and split execution. True cost is fees plus spread plus slippage plus funding, and only the total tells you whether a venue or a habit is cheap.
Educational content only, not investment advice. Fee rates, order types and tolerance settings change; verify current behaviour on your exchange's official pages before trading.
