Adam Ozimek gives some wise investment advice:
If you are someone who is getting ready to retire, and you see 17% returns on your portfolio you should be terrified, not proud, because the investments which you will shortly be living off of are clearly exposed to large amount of risk. There is no magic that brings large returns without risks. Where you see one, there will almost certainly be the other. So if you don’t like huge risks, be wary when you see huge returns.