Learn the stock market › The stock market from zero › Lesson 7 of 9
What is market cap?
The largest US companies
The ten largest of the US companies we show, at the latest close.
| Company | Market cap | Price |
|---|---|---|
| Apple | $4.98 trillion | $342.37 |
| Nvidia | $4.51 trillion | $186.64 |
| Microsoft | $3.94 trillion | $530.61 |
| Alphabet | $3.50 trillion | $284.78 |
| Amazon | $2.80 trillion | $259.30 |
| Meta | $1.56 trillion | $610.15 |
| Tesla | $1.42 trillion | $358.22 |
| Broadcom | $1.40 trillion | $293.69 |
| Berkshire Hathaway | $1.22 trillion | $570.89 |
| Eli Lilly | $1.21 trillion | $1,354.00 |
The price says nothing about size
One Eli Lilly share costs $1,354.00 and one Nvidia share $186.64. Yet Nvidia is valued at $4.51 trillion and Eli Lilly at $1.21 trillion. Nvidia simply has more shares.
A low price doesn't mean a stock is cheap, and a high one doesn't mean it is expensive. What the market pays for a company's earnings is shown by the P/E ratio.
Why market cap changes
The number of shares is nearly always the same from one day to the next, so market cap follows the price. If the price rises 1%, so does market cap. If a company has several share classes, they all count.
Market cap isn't money the company has. It is what all the shares would be worth at the last price, though nobody could sell them all at that price at once.
Companies are often grouped by market cap into large, mid and small caps. Smaller companies often move more.
Test yourself
Company A trades at $500 with 10 million shares. Company B trades at $50 with 200 million shares. Which is larger?
See more companies: the stock pages.