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How the Stock Market Works

The stock market can feel mysterious, but the core idea is simple: it's a marketplace where people buy and sell tiny ownership slices of companies, and prices move with supply and demand.

See it in action: Watch supply and demand move prices live in the simulator.

What is a stock?

A stock (or share) is a fractional piece of ownership in a company. Own one share of a company with a million shares and you own one-millionth of it — including a claim on its future profits. Companies sell shares to raise money; investors buy them hoping the company grows.

What is a stock exchange?

A stock exchange — like the NYSE or Nasdaq — is the organized marketplace where shares change hands. It matches buyers with sellers and publishes the price of every trade. Per the U.S. Securities and Exchange Commission, exchanges exist to make trading fair, orderly and transparent.

Why do prices move?

Price is simply where buyers and sellers agree. If more people want to buy a stock than sell it, the price rises; if sellers dominate, it falls. News, earnings, interest rates and plain emotion all shift that balance second by second — which is why our games model price as a random walk with drift.

The bid, the ask, and the spread

At any moment a stock has a bid (the highest price a buyer will pay) and an ask (the lowest a seller will accept). The gap between them is the spread. Try quoting both sides yourself in the market-making drill.

How to practice safely

You don't need real money to learn. A stock market simulator lets you buy, sell and feel real price swings risk-free. It's the same reason pilots train in simulators before flying.

FAQ

Frequently asked questions

How does the stock market work in simple terms?

It's a marketplace where people trade small ownership stakes (shares) in companies. Prices rise when buyers outnumber sellers and fall when sellers dominate.

Why do stock prices go up and down?

Because price reflects the constant tug-of-war between buyers and sellers, driven by news, earnings, expectations and emotion.

What's the safest way to learn?

Practice with a free simulator or paper trading before risking real money.

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