Skip to main content Skip to main content
Not investment advice. Educational reading. See Disclaimer.
L.2 · BEGINNER · 2 MIN

How Stock Exchanges Work

Stock exchanges like the NYSE and NASDAQ are marketplaces where buyers and sellers meet to trade shares.

Quiz · 5 questions ↓
§ 01

Every trade requires both a buyer AND a seller agreeing on a price. No agreement, no trade.

§ 02
TermDefinitionExample
BidHighest price a buyer will pay$49.95
AskLowest price a seller will accept$50.05
SpreadDifference between bid and ask$0.10
§ 03

Large companies like Apple have penny-wide spreads. Smaller companies can have spreads of $0.50 or more, which means buying and immediately selling costs you money.

§ 04
In the Ticker view, look at the **bid/ask prices** near the top. Notice the spread. Compare AAPL (large-cap) to a smaller company.
§ 05
A stock that normally trades with a 5-cent bid-ask spread suddenly shows a 4-dollar spread during a flash-crash event. What does this widening most directly signal?
§ 06

The spread is a hidden cost of trading. Tighter spreads mean lower costs, which is why large, liquid stocks are cheaper to trade.

Five questions · AI feedback

Sit with the ideas.

A stock has a bid of $49.95 and an ask of $50.05. If you want to buy immediately, what price do you pay?

Why:
Try this in paper trading

Open your first paper position

Pick a company you already buy from — Apple, Costco, Disney, whoever — and paper-buy 10 shares. Write down WHY you'd own it: what they sell, why you'd be a customer, why you think the business will still be around in 10 years.

Open paper portfolio →

Practice mode — simulated trades, not investment advice.

See it on a real ticker →