# Market Basics

> How financial markets work: exchanges, brokers, the order book, bids and asks, market makers and how millions of orders become one live price.

Source: https://learn.tradelabsai.com/markets/market-basics/  
Track: Markets and Instruments · Level: Beginner · Updated: 2026-10-03  
Publisher: TradeLabs AI (https://tradelabsai.com). Education, not financial advice.  
Cite as: TradeLabs Learn, "Market Basics", https://learn.tradelabsai.com/markets/market-basics/

A financial market is a place, physical or electronic, where buyers and sellers agree on prices. The price you see on a chart is simply the last price at which a buyer and a seller agreed to trade. Understanding how that agreement happens explains almost everything a beginner finds confusing: why there are two prices, why your order sometimes fills worse than expected and why prices can jump.

## Who is in the market

Every market has the same cast of characters, even if the names change:

- **Exchanges and trading venues** run the matching system where orders meet. The New York Stock Exchange and Nasdaq are exchanges; crypto has its own, such as Coinbase and Kraken. See [Exchanges](https://learn.tradelabsai.com/market-structure/exchanges/).
- **Brokers** connect you to those venues. You send your order to a broker, and the broker routes it to a venue. See [How to Choose a Broker](https://learn.tradelabsai.com/industry/how-to-choose-a-broker/).
- **Market makers** stand ready to both buy and sell, all day, and earn the small difference between the two prices. They are the reason you can usually trade instantly. See [Market Makers and Liquidity Providers](https://learn.tradelabsai.com/market-structure/market-makers/).
- **Investors and traders** of every size, from someone buying one share to a pension fund buying millions.
- **Clearing houses** stand between buyer and seller after the trade so that each side gets paid even if the other fails. See [Clearing Houses and Central Counterparties](https://learn.tradelabsai.com/market-structure/clearing-houses/).
- **Regulators** such as the SEC and CFTC in the United States set the rules.

## A short history

Organized markets began as people meeting in person. In 1792, 24 stockbrokers in New York signed the [Buttonwood Agreement](https://en.wikipedia.org/wiki/Buttonwood_Agreement), named after the tree on Wall Street they traded under. It set common commissions and grew into the New York Stock Exchange. For most of the next two centuries, trading meant shouting in a crowded room. Today almost all trading is electronic: computers match orders in millionths of a second, and the trading floor survives mostly for television.

## The order book: where prices come from

At the heart of every electronic market is the **order book**: a live list of everyone waiting to buy and everyone waiting to sell.

- A **bid** is an offer to buy at a stated price. The highest bid is the best price anyone will pay right now.
- An **ask** (also called an offer) is an offer to sell. The lowest ask is the cheapest price anyone will sell at right now.
- The gap between the best bid and the best ask is the **spread**. It gets its own lesson: [Bid-Ask Spread](https://learn.tradelabsai.com/markets/bid-ask-spread/).

*Figure: A simple order book. Each row shows a price and how many shares are waiting there.*

When someone sends an order that crosses the spread, a trade happens. If you send a buy order at the market price in the book above, you buy from the cheapest seller at $100.02. That trade prints on the chart as the new last price. A moment later, someone sells at market to the best bid at $99.99, and the last price ticks down. This back and forth is why a chart wiggles even when nothing important is happening.

## Makers and takers

There are two ways to participate in the order book:

- **Makers** place orders that wait in the book, such as a [[limit-orders|limit order]] to buy at $99.98. They add liquidity.
- **Takers** send orders that trade immediately against waiting orders, such as a [[market-orders|market order]]. They remove liquidity.

Many venues pay makers a small rebate and charge takers a small fee. As a trader, you choose which role to play on every order, and that choice is the first real cost decision you make. The full menu of choices is in [Order Types Explained](https://learn.tradelabsai.com/orders/order-types-explained/).

## Liquidity: how easy it is to trade

A market is **liquid** when there are many orders close to the current price, so you can buy or sell a reasonable amount without moving the price. Large company stocks, major currency pairs and Bitcoin are very liquid. A small company stock or an obscure token may have only a few orders, far apart.

**Example: Why liquidity matters**
In a liquid stock, buying 500 shares might fill entirely at the best ask. In an illiquid one, the first 100 shares fill at $10.05, the next 200 at $10.12 and the last 200 at $10.30, because you used up each price level and had to go further up the book. The extra cost is called [Slippage](https://learn.tradelabsai.com/markets/slippage/).

Liquidity changes during the day. It is usually thinnest right at the open, at the close and overnight. Read [Liquidity](https://learn.tradelabsai.com/markets/liquidity/) for how to judge it before you trade.

## When markets are open

Most stock exchanges keep fixed hours. The NYSE's regular session runs from 9:30 a.m. to 4:00 p.m. Eastern time on weekdays, with extended sessions before and after that carry less liquidity ([NYSE hours and calendars](https://www.nyse.com/markets/hours-calendars)). Forex trades around the clock from Sunday evening to Friday evening because banks in different time zones take turns. Crypto never closes. See [Trading Sessions](https://learn.tradelabsai.com/markets/trading-sessions/) for why the time of day matters to your fills.

## What happens after you trade

When your order fills, you own the asset immediately for trading purposes, but the official transfer of cash and securities, called settlement, follows later. US stocks settle one business day after the trade (known as T+1) since May 2024. The clearing house guarantees both sides in between, which is why you never have to worry whether the stranger who sold to you will deliver. More detail is in [Settlement](https://learn.tradelabsai.com/markets/settlement/).

## Key takeaways

- The price on a chart is the last agreed trade, not a fixed value.
- There are always two live prices: the best bid and the best ask.
- Market orders take liquidity and pay the spread; limit orders make liquidity and may not fill.
- Liquidity decides how much your own trading moves the price.

Next, learn exactly what you own when you buy a share in [What Is a Stock?](https://learn.tradelabsai.com/markets/what-is-a-stock/), or go deeper on the two prices in [Bid-Ask Spread](https://learn.tradelabsai.com/markets/bid-ask-spread/).

## Frequently asked questions

### Who sets the price of a stock?

Nobody sets it directly. The price is the last level at which a buyer and a seller agreed to trade. When more people want to buy than sell at the current price, buyers bid higher and the price rises, and the reverse when sellers are more eager.

### What is the difference between an exchange and a broker?

An exchange runs the system where buy and sell orders are matched. A broker is the company that holds your account and sends your orders to exchanges or other venues on your behalf. Individuals almost always trade through a broker.

### Why are there two prices for a stock?

The bid is the highest price a buyer is willing to pay right now, and the ask is the lowest price a seller will accept. You buy at the ask and sell at the bid. The gap between them is the bid ask spread.

### What time does the stock market open?

The New York Stock Exchange and Nasdaq hold their regular session from 9:30 a.m. to 4:00 p.m. Eastern time on weekdays, with extended sessions before and after. Forex trades around the clock on weekdays and crypto trades every day.

## Sources

- U.S. Securities and Exchange Commission, [How stock markets work](https://www.investor.gov/introduction-investing/investing-basics/how-stock-markets-work)
- New York Stock Exchange, [Hours and calendars](https://www.nyse.com/markets/hours-calendars)
- Wikipedia, [Buttonwood Agreement](https://en.wikipedia.org/wiki/Buttonwood_Agreement)

## Continue learning

- Next lesson: [What Is a Stock?](https://learn.tradelabsai.com/markets/what-is-a-stock/)
- Related: [What Is Trading?](https://learn.tradelabsai.com/start-here/what-is-trading/): Trading means buying and selling assets to profit from price changes. Learn how it works, who trades, what moves prices and the real risks involved.
- Related: [Exchanges](https://learn.tradelabsai.com/market-structure/exchanges/): Exchanges are regulated marketplaces where buyers and sellers trade. Learn what exchanges do, the major ones worldwide, how they make money and listing rules.
- Related: [Bid-Ask Spread](https://learn.tradelabsai.com/markets/bid-ask-spread/): The bid-ask spread is the gap between the best price to buy and the best price to sell. Learn how to read it, what it costs you and how to pay less of it.
- Related: [Liquidity](https://learn.tradelabsai.com/markets/liquidity/): Liquidity is how easily you can trade without moving the price. Learn the signs of a liquid market, how illiquidity costs you and when liquidity disappears.
- Related: [The Order Book and Market Depth](https://learn.tradelabsai.com/market-structure/the-order-book-and-market-depth/): The order book lists every waiting buy and sell order by price. Learn to read market depth, what imbalances show, spoofing risks and how depth affects fills.
- Related: [Trading Sessions](https://learn.tradelabsai.com/markets/trading-sessions/): Markets have sessions with different liquidity and volatility. Learn stock market hours, extended hours, the forex sessions and how timing affects your trades.
- Related: [What Is a Stock?](https://learn.tradelabsai.com/markets/what-is-a-stock/): A stock is a share of ownership in a company. Learn what owning a share gives you, why stock prices move, common vs preferred shares and how to trade them.
