I like to trade vertical spreads on the S&P 500 on Thinkorswim. Is there a way when filling in the order rules when attemping to buy a spread to use the S&P price as a limi? I am only able to enter a Mark price. I am trying to buy a spread when the S&P gets to a certain value and when that value is hit I have no idea what the Mark price will be. If anyone can help me I would great appreciate it. Thank you

Have you tried the help desk (phone or chat?)

Sorry I only trade /6E

-Bill

rcaponeg 

I like to trade vertical spreads on the S&P 500 on Thinkorswim. Is there a way when filling in the order rules when attemping to buy a spread to use the S&P price as a limi? I am only able to enter a Mark price. I am trying to buy a spread when the S&P gets to a certain value and when that value is hit I have no idea what the Mark price will be. If anyone can help me I would great appreciate it. Thank you

See if this does the trick: