On a stock market, a company's market cap can indicate how well it is doing — just like that, crypto market cap might be a good barometer for crypto investors. A growing market capitalization means investors are positive about a coin and are willing to invest — so if you're in two minds whether to buy Bitcoin or not, the chart of Bitcoin market cap might come in handy. It displays the total value of Bitcoin which is the number of coins in circulation multiplied by their price — analyzing this line can give you an idea of how Bitcoin is doing and where it's heading.