There might be a misunderstanding of some concepts or perhaps not.
IV will be calculated and driven from market prices. The market prices used may be the bid,ask,last,mid point etc. hence minor variations between brokers.
However, from the phrasing, I'm not sure this is the origin of your query.
You want to know "how to get the pricing right" by which, do you mean you want to get the dollar price of the option(s) right or the IV "pricing"?
Once again, the
Implied Volatility is derived from the market prices...so the dollar pricing is already there...
If you are referring to calculating
theoretical option prices then that requires you estimate a value for volatility to enter into the model which will then output option prices for you. By default, OX uses ATM IV for the default estimate as the input across all strikes (i.e. no skew is modeled) IIRC.
The value for volatility that you enter is not dependent on any broker, only you.
Perhaps some more clarification is required...
MoMoney.
Quote from a529612:
Where can you get the most reliable IV for pricing options? I compared theo value quotes from Etrade (Reuters feed) and OX. The IV are always slightly different: Etrade being higher and OX being lower. How do you know which one is more accurate if you want to get the pricing right?