Haha, I love guessing. As Deprived mentioned, 5% would actually be very nice considering the size of the fund. I have similar experience - I do occasional trades for my friend who's lent me some money to play with, and I always earn more on his account than on my own (relatively) - simply because there's significantly less money and it's easier to move it around. The fund's size is bigger still, so it will be even more difficult (although the manager probably spends a lot more time on it than I do, so it's possible to meaningfully invest the capital).

The true test though will be the comparison with Just-Dice. While I don't remember what their profit was a month ago; if their luck had been 100% (I think it was a bit higher), their profit would have been ~3,4% (assuming 170k wagered and 50k in the bank; sorry for the estimates) for the month.

EDIT: their real profit was ~1800 BTC (thank you Deprived for keeping the score!), but average bank might have been a bit higher (than 50k) too, so 3,4% monthly profit is a good guess.

I give BTC-Growth a 2,5% estimated appreciation. If it is anything over 4%, the manager is a boss, beating a casino.