Market Order or Limit Order on a Crypto Exchange: Which One Costs You More?
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5 min read
You see a coin at 100 on the screen. You tap buy for 2 coins. You expected to pay 200. The exchange charges you 203.
Nothing broke. You used a market order on a thin order book. This post shows what happened, and how a limit order changes the result. The numbers below are made-up examples to show the mechanics, not live prices.
An exchange keeps a list of everyone who wants to buy or sell a coin. This list is the order book.
Sellers sit on one side. Each seller names a price and an amount. These are called asks.
Buyers sit on the other side. Each buyer also names a price and an amount. These are called bids.
The lowest ask and the highest bid sit closest together. The gap between them is the spread. Our guide to the bid-ask spread as a hidden trading cost covers that gap in detail.
Here is a thin book for a made-up coin, XYZ:
| Side | Price | Amount available |
|---|---|---|
| Ask | 104.0 | 2.0 XYZ |
| Ask | 101.0 | 1.0 XYZ |
| Ask | 100.0 | 0.5 XYZ |
| Bid | 99.5 | 1.0 XYZ |
| Bid | 98.0 | 2.0 XYZ |
The "price on screen" is usually the best ask, 100.0. But only 0.5 XYZ is for sale at that price.
A market order says: buy now, at any price available.
The exchange fills it by walking up the asks, cheapest first. Say you buy 2 XYZ:
| Step | Amount | Price | Cost |
|---|---|---|---|
| 1 | 0.5 | 100.0 | 50.0 |
| 2 | 1.0 | 101.0 | 101.0 |
| 3 | 0.5 | 104.0 | 52.0 |
| Total | 2.0 | 203.0 |
Your average price is 101.5, not 100.0. You paid 3.0 extra, which is 1.5% more than 2 coins at the screen price.
That extra cost comes from a thin book. When few coins are for sale, a big order eats through the cheap prices and reaches the expensive ones. This is often called slippage. If you want to see how it works on decentralised exchanges, read about slippage on a DEX. That one covers automated pools, not order books.
A market order has one big plus. It fills right away. Its big minus is that you do not control the price.
A limit order says: buy, but only at this price or better.
Say you place a limit buy for 2 XYZ at 100.0. The exchange matches it with the 0.5 XYZ asking 100.0. The other 1.5 XYZ cannot be filled at your price, so it waits in the book as a bid.
Your cost for the part that filled is 50.0, at exactly 100.0 each. The 1.5 XYZ left over fills only if sellers come down to your price. If they never do, it may never fill.
So a limit order flips the trade-off. You control the price. You do not control whether, or when, you get filled.
Exchanges also care about which kind of order you place.
An order that waits on the book adds to it. That order is a maker. An order that trades right away takes from the book. That order is a taker.
Binance explains that market orders are always takers, because they never rest on the book. It also says exchanges often charge makers less than takers, and that a limit order is not automatically a maker order (Binance support FAQ, seen through search summary on 26 October 2026).
Why? If your limit price is already available, it fills at once, and you pay the taker fee. Fee rates differ by exchange and by account, so check your own fee schedule instead of assuming.
It depends on the book and on what you want.
A simple habit helps. Before you tap buy, look at how much is for sale near the best price. Compare that to the size of your order.
Pick a coin you already trade, such as Bitcoin. Look at your last few buys and compare the price you paid with the price on screen at that time. The gap is your real trading cost.
Log those trades in your NetWort dashboard. Your average buy price and profit and loss will then reflect what you actually paid, fees included.