He invested BTC79.9924*$21.5 (median price that day) = $1719.84
And he cashed out BTC28.3309509*$75.41 = $2136.43
He'd be better off putting those 79.9924 BTC into cold storage and just selling it today without having it go through S.DICE. Then he'd have $6,997 now instead of $2136.43.