What is a stock, really

A share of stock is a slice of ownership in a company. Buy one and you own a genuine, if tiny, piece of the business — its buildings, its brand, its profits. That is the whole idea, and almost everything confusing about trading comes from the gap between owning a piece of a business and watching a number move on a screen every second.

What you actually get

Two things, mostly. A claim on a fraction of the company’s future profits — sometimes paid out directly as a dividend, more often reinvested in the hope of making the whole thing worth more. And a vote, proportional to how much you hold, which for anyone reading this is a rounding error. What you do not get is any say in how the company is run, any access to its cash, or any guarantee whatsoever.

Where the shares come from

A company sells shares to raise money — to build a factory, hire people, pay earlier investors. After that first sale, it is done: the shares trade between investors, and the company gets nothing further from you buying one. The price you see all day is other people trading with each other about a business that is off doing its own thing.

So why does the price move every second?

Because the price is not the company’s value. It is what the most eager buyer and the most willing seller agreed on, most recently. Expectations shift, someone needs cash, a rumour lands — and the number moves while the factory carries on exactly as it was. Over years the price tends to follow how the business actually does. Over an afternoon it follows mood.

Can it go to zero?

Yes. Shareholders are last in line: if a company fails, lenders, suppliers and staff get paid from whatever is left, and equity holders get what remains, which is often nothing. This is not a rare theoretical event — companies go under regularly. It is the reason a share can pay more than a savings account, and the reason it might pay nothing at all.