"Actually the Box, the ISE and the CBOE can all price improve but this is only for single options and not for spreads. If you direct your order to an exchange it is no longer eligible for price improvement. If you are referring to spreads the reason that we route a lot of your orders to the ISE is that they are totally electronic thus providing for faster cancels. I hope this helps, Scott Sheridan" An e-mail from TOS
I also found that my broker (ameritrade) has greeks completely different from TOS. Ameritrade shows a delta of 50 whereas the same portfolio using TOS shows a delta around 7. How come it has this big difference? I don't really know which one to trust.
Ameritrade is a stock broker for the average investor. ToS was founded by former option market makers and floor traders who worked on designing a great trading platform as well as one with many option analytical tools... I think it is pretty easy to decide who to trust...
It may be a matter of decimal places. A delta of 30 is shown in TOS as 300.00. But you should be able to eyeball it. A delta of 50 is ATM while a delta of 7 is several strikes OTM.
Let me see if I understand it. For a portfolio with a delta of 50, what does it mean? Does it mean that the portfolio will change by $50 with a change of 1 point in the underlying? (My porfolio has over 10 legs with rut, so it is better to look at it in terms of dollar amount)
Not to beat a dead horse, but simply put - you cannot continue to use Ameritrade if you are serious about trading options .... perid. Hope you change your broker soon, you'll know what I am talking about once you do.
You might want to check out the following "chats" from TOS: http://www.thinkorswim.com/tos/displayPage.tos?webpage=onlineSeminar