If I didn't read wrong some one has to lose , can be two winners , right ?
With if, it's better
It's based on mutual trading
If the bets are balanced
User 1: bet 100 on the drop
User 2: bet 100 on the rise
The winner earns 200
If the bets are not balanced
User 1: bet 200 on the drop
User 2: bet 100 on the rise
If the winner is User 1 ,he earns 200 and is Refunded 100
The user 2: loss 100
If the winner is User 2,he earns 200
The user 1: loss 100 and is Refunded 100
To overcome this unbalance an automatic counter-bet system will be set up at the beginning(with a limit amount).
The more user there is the less bet refunded