Quote from opt789:
May I ask what JBO you are with? Speaking for options, not stock, no one can calculate their margins in seconds with regard to JBOs or Portfolio Margin.
The calculations are the same for both via the OCC, and because of the multitude of stochastic variables that are not know until after the close of trading it is impossible to do anything other than estimate your Haircut requirements with JBOs or Portfolio Margin.
The difference between the JBO and customer Portfolio Margin is simple as far as exchange minimums go: JBOs now have to cover more than customers, e.g.
in SPX, JBO=+10%, -10% ; PM= +6%, -8%
in NDX, JBO= +15%, -15% ; PM= +10%, -10%
Specific examples:
If you are short 25 SPX April 1360 Puts your JBO requirement is about $176k while your basic Portfolio Margin is $114k, a difference of (176-114)/114 = 54%.
If you are short 25 SPX April 1470 Calls your JBO requirement is about $263k while your basic Portfolio Margin is $121k, a difference of (263-121)/121 = 117%.
JBOs can offer many advantages that customers will never get, but the basic requirements are much more in the favor of Portfolio Margin.