I don't see how the total amount of money stays the same. I suppose that's true if everyone tries to actually liquidate their stock holdings, but the value can and does increase even without any significant new money added to the system. Example: There are 10 shares of corp X at $10 per share. $100 was spent to initially buy these shares. 2 New investors come along and both want to buy the shares. Only 1 share is actually available for trading. Neither has actually purchased a share, but their bidding drives up the price to $15 a share after which one investor actually purchases it. Original owner spent $10, so he takes his $10 out of the market, and new owner puts $15 in, net total of $5 more money in the market. Total value of the company is $150, a gain of $50, even though only $5 of new money was added. Sure, if every share owner decided to liquidate, and there was no money to gobble it up, then prices would go to 0, but as long as the market continues to exist, it can create more wealth than the actual money put into it.