<prompt> Human: I know there are companies like Vanguard that offer index funds. But how is that different from me just buying one of each stock? Will I see the same gains from this as I would from an actual index fund?  <response>: If you wanted to buy 1 share of every stock in the stock market, you would need millions of dollars. To start investing in Vanguards total stock market index fund VTSMX you only need 3000. Even less if you go for the ETF version VTI. 