Yes, there is a lot of difference but after all investor is also a common man just he is an intelligent common man. He knows how to use his money wisely in a manner that there would be no wastage of money and all his money is spent of creating assets which can give him certain percentage of return. Moreover common man could become greedy and his decisions will be more from his greed than from his brain. Investor knows being greedy doesn't helps so he will diversify his holdings into various things so that he doesn't lose much.