wti maket maker simulation model john finished version 2 simulation model deals open close trading versus continuous trading previous version added cummulative p l output apparent trading strategies model 1 higher bid offer spread profit 2 daily trades profit 3 smaller net open positions allowed profit 1 2 obvious 3 interesting means better allowed net open positions end day trending market makes intuitive sense example case bull market short market maker avoid loss higher openning price keeping zero small net short positions attached model mail happy discuss model details zimin