Direct Answer
A limit order is an instruction to buy or sell a stock only at a specified price or better, a buy limit executes at that price or lower, a sell limit at that price or higher. It trades certainty of execution for price control: the order may never fill, or may only partially fill, if the market doesn't reach the limit price with enough available shares.
Key Takeaways
- A buy limit order can only execute at the limit price or lower; a sell limit order only at the limit price or higher.
- Reaching the limit price does not guarantee execution, available shares and order priority still matter.
- An order can be partially filled if only some shares are available at the qualifying price.
- Limit orders help reduce unexpected slippage by capping the worst acceptable execution price.
What Is a Limit Order?
A limit order is an instruction to buy or sell a stock only at a specified price or better.
A buy limit order can execute at the limit price or lower. A sell limit order can execute at the limit price or higher.
Buy Limit Order Example
A stock currently trades at $52. You want to buy it only if the price falls to $50 or less, so you place a buy limit order at $50 for 100 shares.
Possible outcomes:
- The stock falls to $49.90: your order may execute at $50 or lower.
- The stock touches $50: your order may execute, depending on available shares and order priority.
- The stock stays above $50: your order does not execute.
- The stock reaches $50 but too few shares are available: your order may be partially filled.
Reaching the limit price does not guarantee execution.
Sell Limit Order Example
You own a stock currently trading at $48 and want to sell only for $52 or more. You place a sell limit order at $52.
The order can execute at $52, $52.10, $53, or any higher available price. It cannot execute below $52.
Advantages and Risks of Limit Orders
Advantages
- Controls the maximum purchase price
- Controls the minimum sale price
- Helps reduce unexpected slippage
- Useful for stocks with wider bid-ask spreads
- Useful when price matters more than immediate execution
- Commonly used for planned entries and profit targets
Risks
- The order may never execute
- The stock may move away without filling the order
- The order may receive only a partial fill
- Other orders may have priority at the same price
- A narrowly placed limit can cause you to miss the move
A limit order may not execute if the market moves beyond the limit before the order can be filled.
When Does a Limit Order Make Sense?
A limit order may be appropriate when you have a specific entry price or profit target, the stock has a wide bid-ask spread, the stock is moving rapidly, you're trading outside regular market hours, or price control matters more than immediate execution.
Many brokerage firms accept only limit orders during extended-hours sessions because liquidity can be lower and price differences can be larger. Exact policies vary by broker, see our extended-hours trading rules guide for pre-market and after-hours specifics.
Why a Limit Order Might Not Fill at Your Price
Touching your limit price on the chart isn't the same as filling. Exchanges match orders using price priority (better prices execute first) and time priority (among orders at the same price, whoever arrived first fills first). If your order is behind other resting orders in that queue, the price can trade at your limit and move away again before your turn comes up, especially on a fast touch that doesn't linger.
Order size and depth at that price level matter too: a large sell order arriving at your buy limit price might get absorbed entirely by orders ahead of yours, leaving nothing for you. For a deeper look at how queue position and order size determine your actual odds of filling, see Partial Fills, Queue Position, and Fill Probability, or estimate your own odds with the Limit Order Fill Simulator.
What Happens on a Partial Fill?
If only some of the shares available at your limit price are enough to fill part of your order, the remaining unfilled shares typically stay open at the same limit price (assuming a day or GTC time-in-force) rather than being canceled. You may end up owning, or having sold, fewer shares than you requested, with the rest still working as a separate resting order until it fills or expires.
Marketable vs. Non-Marketable Limit Orders
A limit order is marketable when its limit price already crosses the current best available price, a buy limit at or above the current ask, or a sell limit at or below the current bid. A marketable limit order behaves much like a market order: it usually executes immediately (or very close to it) against existing quotes, but still can't execute worse than your limit price.
A non-marketable limit order sits away from the current price (a buy limit below the ask, a sell limit above the bid) and rests in the order book waiting for the market to come to it. Non-marketable orders have execution uncertainty; marketable ones trade off that speed against giving up some of the price control a limit order is meant to provide. Compare both order types head-to-head in Market vs. Limit Orders: The Execution Tradeoff.
What Happens to a Limit Order Across a Price Gap?
A limit order can only fill at your price or better, it never fills at a worse price, but a gap (say, overnight news that moves a stock from $48 to $55 before the next session opens) can mean your order fills at a much better price than expected, fills only partially, or doesn't fill at all if the market never trades back through your limit. A sell limit at $52 placed before a gap-up open could fill near $55 instead of $52; a buy limit at $50 that never gets revisited after a gap-down to $40 simply sits unfilled at the old price. See Liquidity Gaps, Thin Books, and Price Discontinuities for how these price discontinuities form and why a limit order is only a partial safeguard against them.
Spreads, Liquidity, and Fill Likelihood
Wide bid-ask spreads and thin order books make non-marketable limit orders less predictable: with fewer shares resting near your price, a small trade can exhaust the queue ahead of you or blow through the level entirely without ever trading at your exact price. Placing a limit order doesn't fix thin liquidity, it just protects you from chasing a bad price while the market decides. See the Quotes, Spreads & Liquidity curriculum for how spreads and order-book depth are measured and what drives them.
Practice Placing a Limit Order
The Order Simulator lets you place a limit order against a randomized price path and see exactly whether, when, and at what price it would have filled, a low-stakes way to build intuition before risking real capital.
The Cost of a Limit Order Is the Fill You Do Not Get
A limit order removes price uncertainty and replaces it with execution uncertainty, and the second cost is easier to overlook because it is invisible. A missed fill leaves no record on the account, so a trader can accumulate a long history of good prices on trades that never happened without ever noticing the pattern.
The way to keep that visible is to log the intent, not just the executions. Recording orders that expired unfilled, along with where price went afterwards, shows whether patient pricing is saving money or quietly excluding you from the moves you wanted.
The misunderstanding is expecting a fill because price touched the limit. Reaching your price means orders traded there, not that yours was among them. Queue position matters: orders resting at that level earlier are filled first, and if the volume at the price is smaller than the queue ahead of you, price can trade through without your order participating.
A limit also offers no protection against the thing it looks like it protects against. Setting a buy limit below the market does not stop the market from falling far below it; it stops you paying more than your price on the way down. In a sharp decline that is a fill you may not want.
Limit Order FAQs
Does a limit order guarantee the price?
A limit order guarantees that an execution will not occur beyond the specified limit price. However, it does not guarantee that the order will execute.
Why did my limit order not fill when the stock reached my price?
The order may not have filled because other orders had priority, too few shares were available, the displayed quote didn't represent an eligible execution, or the price moved away before your order could be completed.
Can I use a limit order to stop a loss?
A normal sell limit order is usually placed above the current market price and isn't designed to trigger after a decline. A sell stop or sell stop-limit order is generally used for a price-triggered exit below the current market.
Do limit orders work after hours?
Many brokerage firms accept only limit orders during extended-hours sessions because liquidity can be lower and price differences can be larger. Exact policies vary by broker.
How long does a limit order stay open?
Most limit orders default to "day" time-in-force and cancel automatically at the close of the trading session if they haven't filled. If you need the order to persist across sessions, set it to good-till-canceled (GTC), which typically remains active for 60 to 90 days depending on your broker.
Should I place a limit order at a round number like $50.00?
Round numbers attract heavy order flow, which cuts both ways. A large queue at a round price means more competition ahead of you and a lower chance your order reaches the front, but it also means the price often pauses there. Placing a buy limit a cent or two above a round number, or a sell limit a cent or two below, is a common way to trade a slightly worse price for a better position in the queue.
What is the difference between a day limit order and a good-till-canceled one?
A day order expires at the end of the session in which it was entered. A good-till-canceled order persists across sessions until it fills, you cancel it, or the broker's own expiry window ends, commonly measured in a couple of months. The practical difference is attention: a resting good-till-canceled order can fill weeks later on news you had not been following, at a price that no longer reflects your original reasoning.
Do limit orders show up on the order book for other traders to see?
A non-marketable limit order routed to a lit exchange generally rests visibly in the book, where the price and size are part of public market data. Orders routed to a dark venue, held internally by a broker, or entered as a hidden or reserve order are not fully displayed. Whether your order is visible depends on your broker's routing and the order instructions you used rather than on the order type by itself.
How does a stock split affect an open limit order?
Handling varies by broker and by corporate action type. Some adjust the price and quantity of resting orders to reflect the split ratio, and some cancel open orders outright before the adjustment takes effect. Because an unadjusted order can end up wildly mispriced relative to the post-split market, the safe practice is to cancel and re-enter resting orders around a split, dividend, or other corporate action rather than assuming the adjustment happened.
References
The order-type definitions and execution mechanics on this page follow long-standing, widely documented U.S. equity market conventions. Key reference sources include:
- U.S. Securities and Exchange Commission, Investor.gov, Types of Orders: investor.gov: the SEC's investor-education explanation of how market, limit, and stop orders work and how price and time priority determine fills.
- FINRA, Order Types and Trading Education: finra.org: the self-regulatory organization's guidance on order types, marketability, and time-in-force conventions used across U.S. brokerages.