I didn't notice that the commission is different for multi-leg orders vs trading each leg individually. I mean the commission is the same when you trade 2 legs individually, or together as a combo. Why do you think it is different?
I trade QQQ bull calls spread. The recent three trades commissions are 29.37, 54.09, and 35.86. 25 contracts each trade. So, average commssion is (29.37+54.09+35.86)/3/(25*2)=0.79.
Single leg commission is usually below 0.4 as i use Prefer Rebate under Smart routing.
Therefore, the combo commission is significantly higher.
I trade QQQ bull calls spread. The recent three trades commissions are 29.37, 54.09, and 35.86. 25 contracts each trade. So, average commssion is (29.37+54.09+35.86)/3/(25*2)=0.79.
Single leg commission is usually below 0.4 as i use Prefer Rebate under Smart routing.
Therefore, the combo commission is significantly higher.