StocksComparison
Market order vs limit order: which one controls what you pay?
A market order buys or sells right away at the best available price; a limit order sets your price but may not fill. See the trade-offs with numbers.
Quick answer
A market order buys or sells right away at the best available price, so it almost always fills but the price is not guaranteed. A limit order sets the worst price you will accept, so you control the price but the order may fill partly or not at all.
Key points
- A market order is filled immediately at the best available price, which can differ from the last price you saw.
- A limit order trades only at your limit price or better, and may never fill.
- Large market orders in thinly traded stocks can fill at several, increasingly worse prices.
- In fast-moving markets or extended hours, a limit order protects you from unexpectedly bad prices.
- Time-in-force settings (day or good-til-canceled) decide how long an unfilled limit order stays open.
What is the difference between a market order and a limit order?#
The SEC defines a market order as an order to buy or sell a security immediately; it guarantees that the order will be executed but does not guarantee the execution price[1]. A limit order is an order to buy or sell at a specific price or better: a buy limit can execute only at the limit price or lower, and a sell limit only at the limit price or higher[1].
| Feature | Market order | Limit order |
|---|---|---|
| What you control | Speed: trade now | Price: your limit or better |
| Will it fill? | Generally yes, immediately | Only if the market reaches your price; not guaranteed |
| Price you get | Best available price; not guaranteed | Your limit price or better |
| Risk | Paying more (or selling for less) than you expected | Missing the trade, or a partial fill |
| Common default | Yes — brokers typically use it unless you choose otherwise | No — you must set the price |
| Extended-hours trading | Not accepted by many brokers | Many brokers accept only limit orders |
From the SEC's order-type pages and bulletins and FINRA's order-types guide[1][2][3][4].
FINRA notes that the market order is the most common type of investor order, and brokerage firms typically enter your order as a market order unless you specify otherwise[3]. So if you never touch the order-type setting, you are probably sending market orders.
Why might a market order fill at a different price than you saw?#
Because the price on your screen is usually the last trade, and the market keeps moving. The SEC warns that the last-traded price is not necessarily the price at which a market order will be executed[2]. A market buy fills at the current ask — the lowest price a seller will accept — and a market sell at the current bid, the highest price a buyer will pay[5]. FINRA adds that you might not get the price you saw or were quoted, especially in fast-moving markets[3].
Size matters too. Parts of a large market order may execute at different prices due to lack of liquidity[2]. Liquidity is how easily shares can be bought or sold without moving the price[6]; see liquidity for more. If there are only 100 shares offered at the best price and you want 500, the rest of your order moves on to higher prices.
Worked example
Buying 500 shares of a thinly traded stock
A hypothetical stock shows sellers offering 100 shares at $10.05, 200 at $10.10 and 500 at $10.40. You want 500 shares. A market order takes the 100 at $10.05, the 200 at $10.10 and 200 more at $10.40. A buy limit at $10.10 takes only the first 300 shares and waits for the rest.
| Order | Shares filled | Total cost | Average price | Shares still open |
|---|---|---|---|---|
| Market buy 500 | 500 | $5,105.00 | $10.2100 | 0 |
| Buy limit 500 at $10.10 | 300 | $3,025.00 | $10.0833 | 200 |
Figures computed in code from the stated inputs; rounded to the nearest cent or tenth.
Had all 500 shares filled at the $10.05 shown at the top of the book, they would have cost $5,025. The market order cost $80 more. The limit order avoided that, but you hold only 300 of the 500 shares you wanted. Neither result is wrong — it depends on whether getting the trade done or controlling the price mattered more to you.
Why might a limit order never fill?#
A limit order can only be filled if the stock's market price reaches the limit price, and the SEC states plainly that a limit order is not guaranteed to execute[2]. FINRA puts it the same way: if the market price fails to match or better your limit price while the order is active, it will not be executed[3]. Reaching your price makes a fill possible, not certain.
How long the order stays active depends on its time in force. Day orders, if not executed, generally cancel at the end of regular trading hours[2]. A good-til-canceled (GTC) order lasts until it is filled in full or canceled[2], though brokers typically set a limit on how many days it can stay active — often many months[7]. A forgotten GTC order can fill long after you stopped thinking about it.
Time-in-force settings you may see
When does each order type make sense?#
The SEC and FINRA describe the trade-off rather than recommend one type. These are the situations where the trade-off usually tips one way or the other:
- A market order fits when getting the trade done matters more than a few cents — for example, a small order in a heavily traded stock or fund during regular hours, when the spread between bid and ask is narrow.
- A limit order fits when price matters more than speed — for thinly traded stocks, larger orders, fast-moving markets, or any time you have a clear maximum (or minimum) price in mind.
- Outside regular hours, many brokerage firms accept only limit orders, to protect investors from unexpectedly bad prices in sessions with less trading[4].
Regular U.S. trading hours run from 9:30 a.m. to 4:00 p.m. Eastern Time[4]. Our note on how stock exchanges work explains where your broker sends either kind of order.
How do stop and stop-limit orders fit in?#
A stop order (also called a stop-loss) is an order to buy or sell once the price reaches a level you choose, the stop price; when the stop price is reached, it becomes a market order[1]. That means it inherits the market order's weakness: in a fast fall, it may sell well below your stop price. A stop-limit order uses the stop to trigger a limit order instead[3], which caps the price but, like any limit order, may not fill.
Decide what matters more
Getting the trade done now (market), or not paying more than a set price (limit).
Check the quote and spread
Look at the current bid and ask, not just the last price. A wide spread favours a limit order.
Choose the time in force
Day orders expire at the close; good-til-canceled orders can stay open for months.
Review the fill
Check the confirmation for the price and number of shares, and cancel any part you no longer want.
What mistakes do beginners make?#
Sending a market order for a thinly traded stock
With few shares on offer, a market order can walk up to much worse prices. Use a limit order when the spread is wide.
Trusting the last price on the screen
The last trade may be seconds or minutes old. Check the live bid and ask before you trade.
Forgetting an open good-til-canceled order
It can fill weeks later, after your plans have changed. Review open orders regularly.
Setting a limit so far away it never fills
A limit order protects your price but may cost you the trade entirely. Decide which risk you prefer.
What else do beginners ask?#
Is a market order guaranteed to fill?
Generally yes — the SEC says a market order guarantees execution but not the price[1].
Can a limit order fill at a better price than my limit?
Yes. A buy limit can fill at the limit price or lower, and a sell limit at the limit price or higher[1].
What is a partial fill?
When only some of your shares trade. It can happen with limit orders, and parts of a large market order can fill at different prices[2].
Which order type is the default?
FINRA says brokerage firms typically enter your order as a market order unless you specify otherwise[3]. Check your app's setting before you trade.
What is the bottom line?#
A market order buys certainty of a trade; a limit order buys certainty of price. In a busy stock with a narrow spread the difference is often a few cents. In a thinly traded stock, a large order or a fast market, it can be much more. Decide which risk you would rather take before you press the button.
Sources
Numbers in brackets in the text point here. Grade A = primary source (regulator, statistics agency, law or official document).
- 1
- 2
- 3
- 4
- 5
- 6
- 7