Traders who place 10 or more trades per day receive 5% rebate on all trades, 15 or more trades 6%. So a bet of 0.1ETH is actually 0.095ETH, and 0.18ETH payout becomes 90% above initial investment (0.095ETH). And if more then 15 trades are made, then payout rises to 92%, which is probably the highest payout in the industry for this type of instrument.