Limit Order
A limit order buys or sells a security at a specific price: buy at the limit or lower, sell at the limit or higher. It may rest, partial-fill, or expire unfilled.
A limit order is an order to buy or sell a security at a specific price. A buy limit can only be executed at the limit price or lower. A sell limit can only be executed at the limit price or higher. It is not a fill promise.
Limit price or better is the instruction
That matching rule is the whole ticket. A buy limit at $53.00 can print at $52.98 if that offer is there. It cannot print at $53.05 as a limit fill, because $53.05 is worse than the cap. A sell limit at $53.00 can print at $53.05. It cannot print at $52.98 as a limit fill.
The quoted market lives in the bid-ask spread. A buy limit below the offer waits. A sell limit above the bid waits. Crossing the spread with a limit is still a limit: you cap the price. You do not convert the instruction into a market order. Urgency without a cap is the other ticket.
Why a limit may not fill
A resting limit is a price, a size, and a time-in-force. If displayed size at your price is smaller than your size, you can receive a partial fill and rest the remainder — or cancel the remainder, depending on the instruction your firm actually supports. Do not invent a house default. How to Use a Broker covers the ticket fields. This page covers the matching rule.
Level 2 quotes show depth on a venue or an aggregated book. They are not a fill. Hidden size, odd lots, and other venues can trade around what you see. A limit that looks in the book can still wait behind a queue. DAY, GTC, IOC, FOK, and session flags are broker and venue products. TODO:VERIFY the names on your ticket. This page does not invent a pre-selected time-in-force, or whether GTC survives Early or Late.
Limit versus market
A market order seeks size now at the current market price and does not cap it. A limit order seeks a price and accepts non-fill. You cannot have both a guaranteed fill and a guaranteed price on the same instruction. Partial fills are still fills. Sixty-six shares at a $53.00 buy limit can print 20, rest 46, and leave a stub you did not intend to carry into a halt or the close. Size the share count first. Then choose the instruction.
Venue clocks are not broker clocks
U.S. listed equity sessions are not one pre-market pool. Early 4:00 a.m. ET versus Early 7:00 a.m. ET is an exchange split (NYSE Arca Early 4:00 a.m.; NYSE / NYSE American Early 7:00 a.m.). IEX pre-market is 8:00 a.m.–9:30 a.m. ET. Regular hours are 9:30 a.m.–4:00 p.m. ET. Late sessions are venue-specific. Overnight 9:00 p.m.–4:00 a.m. ET is planned for December 6, 2026, not live as of 2026-08-25. Read U.S. session hours 2026.
A broker window that opens at 7:00 a.m. is not the market. It is that firm’s customer access. Broker overnight is ATS access, not exchange overnight. Pre-market trading is the early continuous tape on venues that are actually open — not a single 4:00–9:30 a.m. clock. Cboe C1 equity-options Global Trading Hours is TBA. Do not treat a stock limit as an options GTH working order. A limit without the session flag your firm requires for Early or Late may sit until Core, or reject. TODO:VERIFY that flag.
EXAMPLE: $10,000 account, 66 shares, buy limit $53.00
Sizing is not the order type. Dollar risk per share is |entry − stop|. Shares = dollar risk divided by that amount, then round down. There is no stock-native calculator on denntech.io. Run it on the risk calculator (crypto UI; treat the unit as shares, round down). Formula: dollar risk per share. EXAMPLE only — not a tape print, not a recommendation, not a fill.
| Input | EXAMPLE |
|---|---|
| Account | $10,000 |
| Risk % | 1% (EXAMPLE, not a required rate) |
| Dollar risk | $100 |
| Buy limit | $53.00 or lower |
| Stop used only for sizing | $51.50 |
| Dollar risk per share | $1.50 |
| Shares (round down) | floor(100 ÷ 1.50) = 66 |
| If offer is $53.00 or lower | 66 can fill at $53.00 or better |
| If offer stays above $53.00 | May not fill |
| If 20 print and the offer lifts | Hold 20, rest 46 |
| $ risk if stop later fills at $51.50 | 66 × $1.50 = $99 |
The limit does not move your stop or the $99 budget. Replacing an unfilled remainder with a market order into a thin Early book is a different instruction.
What this page is not
Not a fill guarantee, and not a claim that displayed Level 2 size is yours. Not broker fee schedules — fees are TODO:VERIFY with the firm. Not overnight as live, not Cboe C1 single-stock options GTH as live, and not a live scanner. /stock-scanner is coming soon.
FAQ
What is a limit order?
An order to buy or sell a security at a specific price. A buy limit can only execute at the limit price or lower. A sell limit can only execute at the limit price or higher. It caps price. It does not promise a fill.
Does a limit order always fill?
No. If contra-side size is not available at the limit or better, the order can rest, partial-fill, or expire. Non-fill is a valid outcome, not a delayed market order.
How is a limit order different from a market order?
A market order seeks an immediate fill at the current market price and does not cap it. A limit order caps the price and accepts that it may not fill. You do not get both guarantees.
Do limit orders work the same in Early, Late, and overnight?
No. Early is a 4:00 a.m. versus 7:00 a.m. exchange split, plus IEX at 8:00 a.m. Overnight 9:00 p.m.–4:00 a.m. ET is planned for December 6, 2026, not live. Broker windows are not venue clocks.
Can I size a limit order with the risk calculator?
Yes for the share count only. Treat the unit as shares, round down. The calculator does not place the order and does not promise a fill at the limit. 1% in the EXAMPLE is not a required rate.
Educational only. Not financial, tax, or legal advice. Not a recommendation to buy or sell any security. Order handling is broker- and venue-dependent. Session clocks can change. Trading stocks can result in loss of capital, including loss of principal. Limits are not a fill guarantee through a thin book or a gap.