I invest in tons of stuff, but I do it very seriously. I started off investing in stocks as a kid (~14) then moved to penny stocks which are much higher risk but much larger returns and I found pretty good success there when I was ~16. I made a couple of grand off of that then stopped investing in stuff for a while. Shortly before I turned 18 I started trading foreign currencies. I made twenty thousand dollars over the course of a few months and cashed out, now I'm a partner on a board of venture capitalists in San Diego who are financing and leading startup biotechnology companies in the area. Since you can't invest in companies with only $20,000 my parents were kind enough to match it so I could get a loan for $100k. So now I have debt before I even start college, but I'm making the payments on it so my credit score is remarkably high for an eighteen year old. I'm also one of the youngest venture capitalists in America, the next youngest person on my board is 38 years old.