[g4rthv4d3r]

that is simply not true. the more you buy stocks in a company, the more its market cap goes up. with higher market cap, it is easier to invest in new businesses, acquire other companies, hire better people through stock incentives, etc...

[scarface74]

Market cap doesn't go up based on people buying shares. You are just trading ownership.

In theory, the market cap of the company is the current value of all future returns.