Just starting playing around with option chain pages. It seems like there is a bug. After you enter a symbol into the underlying box in the underlying portion of the window I can't change or add any other underlying symbol. How is this supposed to work. Also, if I try entering ES for options on emini's, it says invalid underlying. Thanks in advance.
You can't do ES on the options chain pages - only equities, not futures. Yes there is an bug. I've simply been avoiding opening positions directly on the options chain page.