A limit order is an instruction to buy or sell at a specific price or better, waiting in the order book until someone trades against it. Controlling the price means giving up certainty of execution. It is the counterpart to a market order, which guarantees execution and surrenders control of price.
How it works
Four steps, with the middle two carrying the difference.
- You set a price and a quantity.
- The order joins the order book at that price level, visible to other traders.
- It sits there until someone trades into it, or until you cancel.
- When matched, it fills at your price or better.
That "or better" clause matters and gets overlooked. Set a buy limit at $100 and it fills at $99.50 if that is what the book offers. Your limit acts as a ceiling on a buy and a floor on a sell, not as a fixed price.
Limit vs market
| Limit order | Market order | |
|---|---|---|
| Price | You set it | The book decides |
| Execution | Not guaranteed | Effectively guaranteed |
| Visible in the book | Yes, while resting | No, executes immediately |
| Fee treatment | Usually the maker rate | Taker rate |
| Main risk | Never filling | Slippage |
Real money sits in that fee row. Most exchanges charge takers more than makers, and some pay makers a rebate, since a book with no resting orders is untradeable. Using limit orders captures the cheaper side.
When a limit order does and does not fill
Reaching your price with someone on the other side is what fills a limit order.
Never reaching your level is the obvious failure. Less obviously, it can also fail when price touches your level briefly while volume ahead of you in the queue absorbs everything available. Order books use price-time priority. Better prices fill first, and among orders at the same price, whoever arrived first goes first.
On larger orders, partial fills are common. A 10 BTC limit order can fill 3 BTC now and leave 7 BTC resting.
Where limit orders help most
- Thin books. On a small-cap altcoin, a market order can climb several price levels. A limit order refuses to.
- Large size relative to daily volume. Splitting a position across several limit orders reduces market impact.
- Volatile conditions. Spreads widen during stress, and a limit order does not chase.
- Fee-sensitive strategies. The maker rate compounds meaningfully at volume.
- Trading around a level. Placing orders at support or resistance rather than watching a screen.
Where they cost you
Here is the trade-off, honestly.
Not filling means an idea you had and did not act on. Should price move away and you chase it later at a worse level, the cheaper fee costs you considerably more than the taker fee would have.
Queue risk applies too. Sitting on the book, your order can be filled by someone trading on information you lack, which is precisely why exchanges compensate makers.
Order variants worth knowing
Post-only. Rejects the order if it would execute immediately as a taker, guaranteeing the maker rate.
Fill-or-kill. Executes the entire quantity immediately or cancels entirely.
Immediate-or-cancel. Fills whatever is available now and cancels the remainder.
Good-til-cancelled. Rests indefinitely until filled or manually cancelled. This is the default on most exchanges.
Stop-limit. A stop-loss order variant that triggers a limit order rather than a market order, protecting your price and risking no fill at all.
What a limit order does not do
- It does not guarantee you get the trade. This is the whole trade-off.
- It does not protect against gaps. If the price jumps past your level without trading there, nothing happens.
- It does not hide your intent while resting. Large limit orders are visible to everyone reading the book.
- It does not work during an outage. During the market-wide crash of 10 October 2025, several venues went down, and orders did not execute.
Put this into practice on mb.io
A limit order is only as good as the book it rests in and the engine matching against it.
mb.io is a regulated crypto spot exchange backed by MultiBank Group, a financial institution founded in 2005 that serves more than 2 million clients across 100+ countries.
- Regulated by VARA in the UAE and AUSTRAC in Australia
- 40-nanosecond execution speed
- 10/10 security score from Hacken, an independent blockchain security auditor
- Institutional-grade MPC custody powered by Fireblocks, with segregated client funds
- A curated list of assets, so you're not trading into thin books on tokens nobody supports
- 24/7 multilingual customer support
Open your account and start trading on mb.io.
Frequently asked questions
What is the difference between a limit order and a market order?
A limit order sets your price and may not fill. A market order fills immediately at whatever the book offers. You are choosing between price certainty and execution certainty.
Why did my limit order not fill?
Either the price never reached your level, or it touched it briefly while orders ahead of you in the queue absorbed the available volume. Order books fill by price first, then by arrival time.
Do limit orders always get the maker fee?
Only when they rest in the book. A limit order priced so it executes immediately against existing orders is charged as a taker, since it removed liquidity rather than adding it.
Can a limit order fill at a better price?
Yes. Your limit is a ceiling on a buy and a floor on a sell. If the book offers better when your order executes, you get the better price.
What is a post-only order?
A limit order that cancels rather than executing if it would fill immediately as a taker. It guarantees the maker fee for traders where fee treatment matters more than execution.
How long does a limit order stay open?
Until filled or cancelled, on most exchanges. That default is called good-til-cancelled. Some venues offer expiry options, and some cancel resting orders after a set period.
Can other traders see my limit order?
While it rests in the book, yes. Size and price are visible to anyone reading depth. Iceberg orders display only a fraction of the true size where a venue supports them.
Should I use limit or market orders?
That depends on whether price or execution matters more for the specific trade, and on how deep the book is. Neither is better in the abstract, and no page can decide it for your situation.
