Quote from spindr0:
Just so we're on the same page, I have used simultaneous ratioed CRB's for earnings plays. I see them referred to as double diagonals and calendar stangles/straddles. I don't care what you call them as long as we're talking about the same beast.![]()
They can be standard (sell near month) or reversed (sell further month). Generally, the standard ones involved buying more long legs and the reversed positions generally involve selling more short legs. And they're usually unbalanced in order to achieve a desired risk profile.
The process involves several components. Near term IV has to be inflated. There has to be horizontal skew (I prefer more than 15 basis pts). A historical pattern of IV contraction is nice but as IV_Trader mentioned and previously discussed, it's of no use now due to last year's market fall and wild IV inflation.
You can just look at the big names (ala AAPL, ISRG, GOOG, etc.). A more comprehensive screening of the list of upcoming EA's takes a lot of leg work... or mouse work. Unless you have access to sophisticated database (fee?) or are adept at programming, it helps if you work in collaboration with someone else.
As to your question, how do you determine the ratio? I plug the strategy into my 2 bit modeling program and graph the position. Perhaps start with a 10/-10/-10/10 position. If it meets certain criteria, it goes forward. Increasing the number of long or short legs alters the risk profile (see bebpasco's RIMM trade). When you find an acceptable one, you're good to go. Then it's only a question of trying to get a better fill via combo orders or legging in.
At some point you're going to have grind out some of these on paper or in a simulator. All the talk in the world isn't going to give you real world insight into how these perform or whether they're suited for your trading. It's a time consuming process to evolve trading strategies and this is certainly one of them.
Spindr, one more question (promise Ill go away and wont come back till Ive done more modelling) you mentioned that you like to see an inflated skew of at least 15 points. Are you referring to your requirements for a calendar or reverse calender here?
