Those results are meaningless because they don't say how many people participated in the contest. I was just in a blackjack tournament where the winner had a return of 2000%. Does that mean that there are blackjack wizards that have mad skillz, and I should give that guy my money to play with?

To OP: At absolute best, this guy is a skilled trader and will, on average, beat the market by 10 points/year. I put a less than 1% chance of that being the case. More likely, he is either a) a lucksack amateur who's done well, and won't beat the market next year, or b) a scam artist. You didn't say where this guy was located or who it was that audited his returns. I don't see any reason why you should have to give him "power of attorney" over your account, and this in particular raises red flags for me. A professional would have an investment vehicle set up where you could deposit directly, like you would with a mutual fund. If you do pursue this further, BE VERY CAREFUL WHAT YOU SIGN, or you could wake up one morning to find he has legally cleaned out all of your accounts.