A stock is a tiny slice of a company. If the company is worth more tomorrow, your slice is worth more too.
Try it
Shares you own10
Company value changes by+12%
−30%0+30%
Each share costs $100 today. Drag the sliders.
You own 10 of 100 slices (10%)
Picture the company as a pie cut into 100 equal slices. Each slice is one share. The blue part is yours. The more you buy, the more of the pie you own.
What you'd have
Your $1,000 became
$1,120
+$120 · +12%10 shares bought at $100 each. The company moved +12%.
What just happenedThe price moved, so your slice moved with it. You didn't do anything. That's owning a stock.