How the Stock Market Actually Works
What a share really is, how a price gets set, and why people invest at all.
A share is a slice of a company
When a company wants to grow, one way to raise money is to sell small pieces of itself to the public. Each piece is a share. Own one and you own a tiny fraction of that business — a claim on its future profits and a vote in some decisions. Own a hundred and you own a hundred slices.
The stock market is simply the marketplace where those slices change hands between people who want to buy and people who want to sell.
Two markets: raising money vs. trading it
It helps to separate two things that both get called 'the market':
- The primary market is where a company first sells its shares to raise money — for example in an IPO (initial public offering). The company gets the cash.
- The secondary market is everything after that: investors buying and selling those existing shares among themselves on an exchange. The company isn't involved in each trade — ownership just moves from one person to another.
Almost all the trading you hear about — the daily ups and downs — happens in the secondary market.
Why bother? The quiet power of compounding
People accept the ups and downs of markets mainly for one reason: over long periods, reinvested growth can build on itself. Each period's gains earn their own gains next period — that snowball is called compounding, and its effect over decades is easy to underestimate.
Play with the calculator below. It doesn't predict anything — it just shows the shape of compounding when a steady, hypothetical rate is applied.
Check your understanding
- A share is a small ownership slice of a company; the stock market is where slices trade.
- A price is simply where a buyer and seller agree — supply and demand, updated constantly.
- Primary market = a company raising money (e.g. IPO); secondary market = investors trading existing shares.
- Compounding — gains earning gains — is powerful over time, but real returns vary and are never guaranteed.