Slippage is the gap between the price you expected and the price you actually got. It grows when a book is thin and an order is large. Understand it and the true cost of trading becomes visible before you act.
Slippage is the difference between the price you expected to trade at and the price you actually received. It happens because a market order takes whatever the order book offers, and on a thin book a sizeable order climbs through several price levels, filling part at the first price and the rest at worse ones. The result is an average fill that is poorer than the quote you saw. Slippage is a cost, separate from fees and from the spread, and it is largest when liquidity is thin, the order is big, or the market is moving fast. You reduce it with limit orders, smaller size, and patience, never by wishing the book were deeper.
When you place a trade you have a price in mind, usually the quote on screen. Slippage is the amount by which your real average fill differs from that. A small drift is normal, a large one is a sign of a thin book or a fast market.
A market order asks to trade now at the best available prices. If there is not enough size at the first price, it fills the rest at the next price, and the next, walking up or down the book. Each step worsens your average.
On a deep book there is plenty of size near the quote, so even a large order barely moves your average fill. On a thin book the same order eats through levels quickly, and the slippage can dwarf the headline spread.
Limit orders cap the price you accept, smaller orders stay within the resting size, and trading calmer markets reduces surprises. None of these removes slippage entirely, but together they keep it from quietly eroding your results.
Imagine a thin book with offers stacked at rising prices. A small market order fills near the first offer. A large one climbs through the levels and fills at a worse average. Drag to see the average fill price and the slippage against the first offer of fifty cents. This is illustrative and excludes fees.
Illustrative only. A thinner book and a faster market both raise slippage. Prices are examples, not a quote or a prediction.
Slippage is the difference between the price you expected when you sent an order and the price at which it actually executed. If you saw an offer at fifty cents and your order filled at an average of fifty one and a half cents, you slipped a cent and a half. It is not a fee and it is not the spread, although both can be present at the same time. It is specifically the cost of demanding more size than rests at the best price.
Slippage can run in your favour as well as against you, since a fast moving market can occasionally fill you better than the quote. In practice, for anyone taking liquidity with market orders, it tends to run against you on average, because you are the one crossing the book and consuming the resting orders. Treating it as a real and usually adverse cost is the safer mental model.
An order book is a live ladder of resting buy and sell orders at different prices. The best offer is the lowest price someone will sell at, and behind it sit more offers at higher prices. When you send a market order to buy, it matches against the best offer first. If your order is larger than the size resting there, the remainder matches against the next offer up, and so on until the whole order is filled.
Your average fill is the size weighted average of every price you touched. A small order that fits inside the best offer fills entirely at that price, with no slippage. A large order that exhausts several levels fills at a blend, and that blend is worse than the first price you saw. The depth of the book, meaning how much size waits at each level, decides how far you climb and therefore how much you slip.
This is why reading the depth before you trade matters as much as reading the quote. The quote tells you the best price for a tiny order. The depth tells you what a real order will actually cost. On a quiet contract the two can be very different.
Three conditions make slippage worse, and they often arrive together. The first is a thin book, where little size rests near the quote, so even a modest order walks through levels. Obscure questions, contracts far from resolving, and prices near the extremes of one or ninety nine cents all tend to be thin.
The second is a large order relative to the resting size. The same book that absorbs a small order with no drift can hand a large order several cents of slippage. The relevant figure is not the absolute size of your order but its size compared with what is resting in the book in front of you.
The third is a fast market. When fresh information arrives, resting orders are pulled and repriced in an instant. An order sent into that moment can fill far from the price you last saw, because the book moved while your order was travelling. Around scheduled news or a resolution moment, slippage and volatility both spike.
The most direct tool is a limit order. Instead of taking whatever the book offers, a limit order names the worst price you will accept and waits. It protects you from a bad fill, at the cost of possibly not filling at all if the market moves away. For anyone worried about slippage, a limit order placed at or just inside the quote is the standard defence.
Sizing to the book is the next tool. If the resting size at the best price is small, breaking a large order into smaller pieces, or simply trading less, keeps you from climbing the ladder. Patience helps too, because waiting for a busier moment, or for liquidity to rebuild after a shock, means more size rests near the quote when you finally act.
Finally, avoid trading into the teeth of a fast move unless you have a clear reason. The convenience of an instant market order is real, but in a thin or volatile market that convenience is paid for in slippage. Folding the likely slip into your thinking before you trade, alongside the spread and any fee, gives you the true cost of the position rather than the flattering headline price. None of this is financial advice.
Take one illustrative book. The best offer is fifty cents, but only a little size rests there, and more size waits at higher prices. A buy order of one thousand contracts cannot fill at fifty cents alone, so it climbs. The diagram below shows how far an order of one thousand contracts eats into each level, and the table puts the same example into numbers. The figures are illustrative and exclude fees.
| Order size | Price levels touched | Average fill | Slippage vs 50¢ best offer |
|---|---|---|---|
| 100 | 50¢ only | 50.00¢ | 0.00¢ |
| 500 | 50¢ to 51¢ | 50.60¢ | 0.60¢ |
| 1,000 | 50¢ to 53¢ | 51.40¢ | 1.40¢ |
| 2,000 | 50¢ to 54¢ | 52.45¢ | 2.45¢ |
The pattern is the point. A small order fills at the quote with no slippage, while each larger order reaches further up the ladder and pays a worse average. The same arithmetic runs in reverse for a sell order walking down the bids. Some order book venues fold a defence against this into the order ticket itself. Myriad runs a central limit order book that lists slippage controls and limit orders among its features, per the Decrypt Myriad guide, as of May 2026, so a trader can cap the worst price before sending. Where you cannot set such a control, a plain limit order does the same job.
Slippage rarely travels alone, which is why it helps to see it next to the other costs of a trade. Our cross platform fees table tracks the trading fees, spreads, and withdrawal terms that sit alongside slippage across the sixteen platforms we cover, so you can weigh the full cost rather than the headline price.
Prediction market prices live between one cent and ninety nine cents, and the two ends of that range behave very differently from the middle. A contract trading near fifty cents is usually the busiest, because the outcome is genuinely in doubt and traders disagree, so the book tends to be deep and slippage on ordinary size is small. A contract trading at three cents or ninety seven cents is a different animal. The crowd has largely made up its mind, fewer traders are active, and the resting size near the quote is often thin, so even a modest order can move your average fill by a noticeable fraction of the price.
The effect matters more at the extremes because the slippage is large relative to the price you are paying. Slipping one cent on a fifty cent contract is a two percent drift on your entry. Slipping that same cent on a four cent contract is a twenty five percent drift, which can swamp the edge you thought you had. Long shots and near certainties are exactly the contracts where a careless market order does the most quiet damage, so they reward a limit order and a smaller size more than any other part of the book. Reading the depth at these prices, rather than trusting the headline quote, is the habit that protects you, and none of it requires predicting the outcome itself.
The ladder above describes an order book, where named prices rest at named sizes and your order climbs from one to the next. Many crypto native venues use a different engine called an automated market maker, and the same cost shows up there under a different name. An automated market maker holds a pool of funds and quotes a price from a formula rather than from resting orders, so the price moves smoothly along a curve as you buy. A small trade barely moves it. A large trade pushes along the curve and fills at a steadily worse price, which traders usually call price impact. It is the same idea as slippage, dressed in different mechanics, and it grows for the same reason, namely a large trade meeting shallow liquidity.
Some platforms run both engines side by side. Myriad, for example, offers central limit order book markets and automated market maker markets, per the Decrypt Myriad guide, as of May 2026, and the company describes the automated market maker curve as making prices more predictable for traders. Whichever engine sits behind a market, the practical question for you is unchanged. Look at how much it would cost to trade your size, not just the price for a single contract, and treat the difference between the two as a real cost of the trade.
Most beginners think about slippage only when they open a position, but the larger surprise often comes when they try to close one. A market that was busy when you entered can be quiet when you want to leave, and a contract approaching its resolution date can thin out as other traders lose interest in a result that already looks settled. If you hold a sizeable position and then send a market order to exit into that thin book, you walk down the bids the same way a buyer walks up the offers, and the slippage can erase part of a gain you thought you had locked in.
The defence is to plan the exit before you need it. Ask whether the market is likely to stay liquid until you want to sell, size the position so that a normal exit does not have to climb through several levels, and prefer a limit order when you are not in a hurry. If the only way out of a position is a large market order into a quiet book, the true cost of that position was always higher than the entry price suggested, and seeing that in advance is far better than discovering it at the moment you most want a clean fill. None of this is financial advice, and a well filled trade can still resolve against you.
It helps to keep three costs apart, because they behave differently and confusing them leads to bad decisions. The spread is the gap between the best bid and the best offer, a cost you pay even on a single contract simply for trading now rather than waiting. The fee is what the platform charges, set by its own schedule and often different for taking liquidity than for adding it. Slippage is the extra cost that appears only when your order is large enough to climb past the best price into worse levels.
On a deep, busy market the spread is tight, slippage is near zero for ordinary size, and the fee may be the largest of the three. On a thin market the picture flips, the spread is wide and slippage can dominate everything else, dwarfing a fee that looked like the main cost on paper. Because the mix changes with the book in front of you, the only reliable habit is to estimate all three for the specific trade you are about to make rather than assuming one of them is always the one that matters.
Putting numbers to it before you trade turns a vague worry into a clear figure. If the spread is two cents, the likely slippage on your size is another cent, and the fee is a known amount, you can add them up and ask whether the position still makes sense at that all in cost. A trade that looks attractive at the headline price can quietly stop making sense once the full cost is visible, and seeing that in advance is the whole point.
Slippage rewards a small amount of preparation. Before sending a market order, glance at the depth, not just the top quote, so you know how far your size will climb. If the resting size near the price is thin relative to your order, that is the moment to switch to a limit order, cut the size, or wait, rather than to discover the slip after the fill.
It also helps to be honest about why you are trading at this exact second. If nothing forces immediacy, patience is free and often pays, because liquidity tends to rebuild and spreads tend to narrow once a busy or volatile moment passes. The traders who suffer most from slippage are usually those who demand instant execution of a large order on a quiet book, which is the single most expensive thing you can do. A short, unglamorous routine of checking depth, sizing to it, and choosing the order type deliberately removes most avoidable slippage, and none of it requires predicting anything.
Reducing slippage lowers your cost of trading, not your risk of loss. A perfectly filled order can still resolve against you. Stake only what you can afford to lose, never to chase a loss, and never on borrowed money. If it stops feeling like a free choice, step back. In the United States you can call or text the helpline on 1-800-GAMBLER or visit ncpgambling.org.
Slippage is the gap between the price you expected and the price you actually got. It appears when a market order takes more size than rests at the best price, filling the rest at worse prices and leaving you with a poorer average fill.
No. The spread is the gap between the best bid and the best offer, a cost you pay even on a tiny trade. Slippage is the extra cost of a larger order climbing through several price levels. You can face both at once, but they are different things.
A limit order caps the price you will accept, so it protects you from filling at a worse price than your limit. The trade off is that it may not fill at all if the market moves away. It controls your price, at the cost of certainty of execution.
A thin market has little resting size near the quote, so even a modest order exhausts the best price and climbs to worse ones. The same order on a deep book would barely move your average fill. Slippage scales with how large your order is relative to the resting depth.
Occasionally a fast market fills you better than the quote, which is slippage in your favour. For anyone taking liquidity with market orders it tends to run against you on average, because you are the one consuming resting orders, so it is safer to treat it as an adverse cost.
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