Exchange
An exchange is an organised marketplace with set rules where buyers' and sellers' orders are matched, such as a stock exchange or a crypto exchange.
An exchange is where the market actually happens. It collects buy and sell orders from many participants, matches them by price and time, and publishes the resulting prices for everyone to see. Exchanges also set the rules: which assets can trade, at what hours, in what sizes. This entry explains how exchanges work, how they differ from brokers and over-the-counter markets, and why the venue matters to your trades.
- Category
- Trading Basics
- Reading time
- 4 min
- Also called
- Stock exchange, Crypto exchange, Trading venue
- Updated
An exchange in plain words
Think of a large, very fast auction room. Buyers say what they will pay, sellers say what they will accept, and the exchange’s matching engine pairs them up. Waiting orders form the order book. See Order Book.
Most individuals do not connect to an exchange directly; they send orders through a broker who is a member of it.1 See Broker.
How an exchange processes a trade, step by step
Listing
The exchange decides which assets can trade and under what rules.2
Order arrives
A broker or member sends a buy or sell order. See Order.
Matching
The matching engine pairs it with opposite orders, usually by best price first, then by time.
Price published
The trade price and size are reported as market data. See Volume.
Clearing
A clearing house confirms the trade and often stands between buyer and seller.
Settlement
Cash and assets change hands, usually a set number of days later. See Settlement.
Worked examples
Example 1 — Price–time priority
MatchingTwo buy orders sit at $20.00: A (placed first, 300 shares) and B (200 shares). A seller sells 400 shares at market.
| A filled | 300 shares |
| B filled | 100 of 200 shares |
At the same price, the earlier order fills first. See Partial Fill.
Example 2 — The same share on two venues
VenuesA stock trades on its home exchange at $50.00 and on another venue at $50.01.
| Price gap | $0.01 |
| Result | Arbitrage traders close it quickly |
Competition between venues keeps prices closely aligned.
Example 3 — A crypto exchange failure
Custody riskA trader keeps all their coins on one crypto platform. The platform halts withdrawals and later fails.
| Access to funds | Frozen |
On some crypto platforms the exchange also holds your assets, so its failure can trap your funds. See Centralised and Decentralised Exchanges.
Exchange vs. other ways to trade
| Aspect | How prices form | Key difference |
|---|---|---|
| Exchange | Public order book, many participants | Transparent prices and set rules |
| Over-the-counter (OTC) | Negotiated between two parties or dealers | Less transparent; flexible terms |
| Dark pool | Hidden orders matched privately | Large trades without showing size. See Dark Pool |
| Decentralised exchange | Smart contracts and liquidity pools | No central operator. See Automated Market Maker (AMM) |
What exchanges provide
Price discovery
Many orders meeting in one place set a fair market price.
Liquidity
Concentrating buyers and sellers makes trading easier. See Liquidity.
Rules and oversight
Listing standards, trading hours and market surveillance. See Market Hours.
Standard contracts
Futures and options exchanges define contract sizes and expiries. See Futures Contract.
Advantages and disadvantages
Advantages
- Transparent prices visible to all participants.
- Clear rules and supervision.
- Central clearing reduces the risk of the other side not paying.
Disadvantages
- Limited trading hours on many exchanges.
- Large orders are visible and can move prices.
- Some crypto exchanges combine roles in risky ways.
- Fees and market-data costs add up for active traders.
Going deeper
Read as far as you need. Each level builds on the one before it.
Many venues, one price
Beginner
Shares often trade on several venues at once. Routing systems and arbitrage traders keep their prices close together.
Auctions at the open and close
Intermediate
Many stock exchanges set opening and closing prices through auctions, collecting orders for a period and then matching them at one price.
Trading halts and circuit breakers
Advanced
Exchanges can pause trading in a stock or the whole market after extreme moves or pending news. See Circuit Breaker and Trading Halt.
Common mistakes
Confusing broker and exchange
They do different jobs and carry different risks.
Leaving all crypto on one platform
Spread custody risk or use self-custody where appropriate.
Ignoring the venue’s hours
Orders may not work outside the session.
Assuming one price everywhere
Thin venues can trade at different prices.
Check your understanding
Test yourself before moving on. Each answer comes with an explanation.
Key points to remember
- An exchange matches buy and sell orders under set rules.
- Orders usually fill by best price, then by time.
- Most traders reach exchanges through a broker.
- Clearing and settlement complete the trade.
- Crypto platforms can combine exchange, broker and custody roles.
Frequently asked questions
Can I trade directly on an exchange?
What is the difference between an exchange and OTC trading?
Why do exchanges have trading hours?
Further learning
- Order Book
The list of waiting orders an exchange keeps.
- Broker
How you get access to an exchange.
- Market Maker
Firms that keep exchange quotes available.
- Liquidity
Why concentrating orders matters.
Sources
This article is written in our own words. The sources below support the specific facts, rules and figures marked with a number in the text. Links open the original publisher’s page.
- Investor.gov (SEC). Broker (glossary) (opens in a new tab) Checked .
- Investor.gov (SEC). National Securities Exchange (glossary) (opens in a new tab) Checked .
Educational content, not financial advice. Examples use hypothetical prices and simplified costs; actual fees, margin rules and regulations vary by broker, market and country. We are not affiliated with any publisher linked above. Last reviewed . Report an error or request a source credit.