If there is a lot of demand on both exchanges when the trade opens, then this will lead to accurate open prices. If they are closing at or below that price then there is not much difference between the purchase price and sale price.
So if you see an open stop limit order one second before your trade starts you can set maximum buy limit at 130000 (or whatever amount you like) and minimum sell limit at 110000 (or whatever amount you like). Then if there is no market makers in exchange B for 20000 BTC, our swap service will automatically increase the size of the bid wall for up to 20000 BTC (to avoid buying above your buy limit), thus ensuring that it’s only profitable through market making after your specified time frame. Alternatively, if anyone wants to reveal their limited amount of coins first then they can choose lower limits than ours.
This also works with stop loss instead of just using open stop limits as shown below….