Market Order
A market order buys or sells a stock at the current market price. You are almost always filled if buyers and sellers are there; the executed price may not be the price you expected.
A market order is an order to buy or sell a stock at the current market price. Unless you specify otherwise, your broker will enter your order as a market order. You are almost always filled if willing buyers and sellers are there. The executed price may not be the price you expected.
Fill now is the instruction
A market order says: take the size that is there, at the prices that are there, now. It is the opposite of a limit order, which caps price and accepts non-fill. You cannot have both a guaranteed fill and a guaranteed price on the same ticket.
Available prices live in the bid-ask spread and in the depth behind it. A market buy lifts offers. A market sell hits bids. If the first level is smaller than your size, the order continues to the next level. That walk is the fill. It is not a single print at the last trade you glanced at. Level 2 quotes are a picture, not a reservation. Size can cancel before your order arrives.
Routing, session flags, and whether the firm even accepts a market order in that window are ticket questions. This page is the matching rule: no price cap, fill at available size.
The fill may not be the price you expected
That is the investor.gov disadvantage, restated as operations. Slippage is the difference between the quote you used to decide and the prices you actually received. This page does not invent a typical spread in cents, a usual slip, or an average Early-session width. Those numbers are tape- and name-specific. If you did not measure them on that name, in that session, you do not have them.
Wide spreads in Early and Late are a qualitative fact of thin books, not a license to publish a made-up width. If the book is one-sided, a market order can print far from the quote you saw. If the book is halted, a market order is not a fill through the halt. See trading halts.
Early, Late, and planned overnight
U.S. listed equity sessions are not one pre-market pool. Pre-market trading is continuous early matching on venues that are actually open. 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. Overnight 9:00 p.m.–4:00 a.m. ET is planned for December 6, 2026, not live as of 2026-08-25. Cite U.S. session hours 2026. Broker windows are not venue clocks. Broker overnight is ATS access, not exchange overnight. Cboe C1 equity-options Global Trading Hours is TBA.
EXAMPLE: where 66 market shares can print
EXAMPLE only — not a tape print, not a typical spread, not a recommendation. Size first. Account $10,000, 1% EXAMPLE risk → $100. Intended buy $53.00, stop $51.50 → $1.50 per share. Shares = floor(100 ÷ 1.50) = 66, round down. Actual dollar risk if the stop later fills at $51.50 = $99. Formula: dollar risk per share. Run it on the risk calculator (crypto UI; treat the unit as shares, round down). The market order does not lock $53.00. It takes offers until 66 shares are filled, or until there is no remaining size in that session.
| Session | Venue clock (as of 2026-08-25) | Market-order note |
|---|---|---|
| Early 4:00 a.m. ET | NYSE Arca Early; other 4:00 a.m. books | Those books only. Spreads can be wide. Do not invent cents. |
| Early 7:00 a.m. ET | NYSE / NYSE American Early | Different open. A later broker window is not this clock. |
| IEX pre-market | 8:00 a.m.–9:30 a.m. ET | Not in the 4:00 / 7:00 split. IEX post ends 5:00 p.m. |
| Regular hours | 9:30 a.m.–4:00 p.m. ET | Core matching. Still no price cap. Size can still walk. |
| Late | Venue-specific | Not one 4:00–8:00 p.m. pool. Thin books can walk. |
| Overnight | 9:00 p.m.–4:00 a.m. ET planned Dec 6, 2026 | Not live. Broker overnight = ATS, not exchange overnight. |
The table is a clock map, not a spread table. If 66 shares take three offer levels, those prints are the fill. This page will not invent the ticks. If a halt is in force, the market order does not print through it.
What this page is not
Not a price cap and not a last-trade guarantee. Not a source of typical spread cents or usual slippage stats. Not one 4:00–9:30 a.m. pre-market pool. Not overnight as live, not Cboe C1 equity-options GTH as live, and not broker fee schedules (TODO:VERIFY).
FAQ
What is a market order?
An order to buy or sell a stock at the current market price. It does not cap the fill. The executed price may not be the price you expected.
Why do market orders slip?
Because available size at the quote you saw may be smaller than your size, already taken, or cancelled. The order then walks the book. This page does not publish a typical-cent figure.
Should I use a market order in Early or Late sessions?
Those books can be thin and the spread can be wide. A market order will still take available prices. That can be a large walk. A limit, by contrast, may not fill. Session clocks are venue clocks, not broker windows.
How is a market order different from a limit order?
A limit order buys or sells at the limit or better and may not fill. A market order fills at the current market price and does not cap it. Choose whether you will skip the trade or walk the book.
Does a market order ignore trading halts?
No. A halt is a halt. When matching resumes, available prices can be away from the last pre-halt print. That is gap risk, not a promised reopen price.
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. Market orders are not a last-print guarantee and are not a fill through a halt.