Quote from Xenia:
15 November 2007
Change in Margin for Short Out-of-the-Money Equity Index Future Options
Please be advised that per IB's plan to more accurately reflect the risk of short out-of-the-money equity index future options, the margin requirements on these products are being incrementally increased. An increase in the weighting factor, from 13.5% to 14.5%, is scheduled for today, 11-15-2007, and will be implemented starting at 10:30AM EST.
To evaluate the potential impact on your commodity margin requirement, take the total (-30%) P/L value from the most recent Stress Test Summary (available in Account Management / Report Management)and multiply it by the weighting factor (in this case 14.5%). This will approximate the new overnight commodity margin requirement. Note - if the SPAN margin requirement is greater, then SPAN will be used. Please manage your risk accordingly
Interactive Brokers Customer Service