A company's total value on the stock market: share price multiplied by every share outstanding.
Market cap is simply a company's share price multiplied by the total number of shares that exist. It's the quickest way to compare company size on the stock market, and it's why "world's most valuable company" headlines shift depending on the day's trading rather than anything the company actually did that day. It's a market's opinion of worth, not a company's cash in the bank, book value, or profit, those are different numbers entirely, and market cap can move sharply on sentiment alone.
Part of the Open Bell Glossary — plain-English explanations of the terms that come up on the show. Browse every term.