How stock exchanges work: NYSE, Nasdaq and market hours

What is a stock exchange?#

A stock exchange is an organized marketplace that brings buyers and sellers of shares together. In the United States, a "national securities exchange" is one that has registered with the SEC under Section 6 of the Securities Exchange Act of 1934 ^[1]. On October 6, 2026, the SEC's register listed 29 exchanges registered under Section 6(a), from New York Stock Exchange LLC and The Nasdaq Stock Market to names such as MEMX and the Texas Stock Exchange (our count of the SEC list) ^[1].

Exchanges are not the only places where shares change hands. FINRA explains that stocks also trade on alternative trading systems, including dark pools, which do not publicly display their prices or order sizes ^[2]. Those trades must still be reported to a FINRA Trade Reporting Facility and published on the consolidated tape ^[2].

Exchanges also play a role in a company's life. When a company goes public in an IPO, investors who miss the offering can buy shares when they are resold in the public market in the days after the IPO ^[3]. What you own when you buy one of those shares is explained in what is a stock.

How is the NYSE different from Nasdaq?#

Both are on the SEC's list of registered exchanges ^[1], but they describe their market models differently. The NYSE assigns one Designated Market Maker (DMM) to each NYSE-listed security, and DMMs have obligations to maintain fair and orderly markets for those securities ^[7]. Floor brokers, employees of member firms, still execute trades on the exchange floor for their firms' clients ^[7].

Nasdaq describes its open and close through its Opening and Closing Crosses, which cross orders at a single price; the Closing Cross sets the Nasdaq Official Closing Price ^[8]. Nasdaq also splits listings into three tiers, the Global Select Market, Global Market and Capital Market, each with its own entry standards ^[9].

Listing standards are entry rules, not endorsements. Nasdaq's January 2026 guide sets a $4 minimum bid price for an initial listing on its Global Select and Global Markets, and a $4 bid price on its Capital Market, or a $3 closing price for companies that meet extra revenue or asset tests ^[9]. Meeting those rules says nothing about whether a stock will rise.

What happens when you place an order?#

You do not usually deal with an exchange yourself. You place the order with your broker, and the broker decides where to send it. The SEC lists the options: an exchange, a market maker (a firm that stands ready to buy or sell a stock at publicly quoted prices), an electronic communications network that automatically matches buy and sell orders, or the broker's own inventory, which is called internalization ^[10].

Your broker has a duty to seek the best execution that is reasonably available for your order ^[11]. Some market makers pay brokers for sending them orders, perhaps a penny or more per share, a practice called payment for order flow ^[11]. You can ask your broker where your orders were routed, and SEC Rule 606 requires it to tell you the venues used in the six months before your request ^[10] [12].

The four places your broker can send an order, as the SEC describes them, are in the table below ^[10].

Source: SEC, Trade Execution: What Every Investor Should Know (2013) ^[10].

The type of order you choose decides how it fills. A market order generally executes immediately but at a price that is not guaranteed, while a limit order sets your price but may never fill ^[13]. The trade-offs are covered in market orders vs limit orders.

What are the stock market hours?#

Nasdaq lists three U.S. trading sessions, all in Eastern Time ^[4]. The NYSE lists the same 9:30 a.m. to 4:00 p.m. core session ^[14]. On Nasdaq, the Opening Cross starts at 9:30 a.m. and the Closing Cross at 4:00 p.m. ^[8]. Nasdaq has also said it will add an overnight session from 9 p.m. to 4 a.m. ET, creating a 23-hour trading day five days a week, so check the current schedule before you rely on the times below ^[15].

Times from Nasdaq's U.S. market schedule ^[4]. Lengths calculated.

When is the stock market closed in 2026?#

U.S. exchanges close on ten weekdays in 2026 and close early, at 1:00 p.m. Eastern Time, on two more, according to Nasdaq's 2026 schedule ^[4]. The full list is in the table below.

Source: Nasdaq U.S. stock market holiday schedule for 2026 ^[4]. Check the exchange calendar for other years.

What happens after the trade?#

A trade can be agreed quickly, but ownership changes hands later, at settlement. The SEC defines settlement as the official transfer of securities to the buyer's account and cash to the seller's account ^[5]. Since 2017 that took two business days (T+2); for transactions on or after May 28, 2024 it takes one business day (T+1) ^[5].

1. Trade date

   Your order is filled. The SEC's example: you sell shares of a company on Monday ^[5].

2. Settlement date

   That sale settles on Tuesday, one business day later ^[5].

3. What it means for you

   Buyers may need to pay for their trades one business day earlier than under the old T+2 cycle ^[5].

Can the whole market stop trading?#

Yes. Market-wide circuit breakers halt trading across the market when the S&P 500 falls sharply. The thresholds are 7% (Level 1), 13% (Level 2) and 20% (Level 3), calculated daily from the index's prior close ^[6]. A Level 1 or 2 fall before 3:25 p.m. halts trading for 15 minutes, and a Level 3 fall at any time halts trading for the rest of the day ^[6].

Mistakes beginners make with stock exchanges#

• Thinking you trade on the exchange yourself

  Your broker routes the order and may never send it to an exchange at all ^[10].

• Treating after-hours prices as tomorrow's open

  Extended-hours prices may not reflect the regular-session close or the next opening price ^[16].

• Forgetting holidays and early closes

  There is no regular session on a market holiday, and two days in 2026 close at 1:00 p.m. Eastern Time. Check the list above ^[4].

• Reading a listing as a seal of approval

  Listing standards such as a minimum bid price are entry rules ^[9]. They do not make a stock safe or likely to rise.

Frequently asked questions#

The bottom line#

A stock exchange is a registered marketplace, but your broker decides whether your order goes there, to a market maker or elsewhere. The regular session runs 9:30 a.m. to 4:00 p.m. Eastern Time outside market holidays, extended hours are thinner and riskier, and trades settle one business day later. Next, follow the steps to buy your first stock, or go back to the stock market basics hub.

Education only. This page is not investment, tax or legal advice. Stocks can lose value. See our risk disclosure.