Actually I think that estimate was wrong... I was hoping you had that info and were just engaging the ET readership...
Try this out -
1130X100X.15X20= 339K - their last bit is hard to calculate, not sure how that works... either way its a lot of money parked for a 3% or so return..
Margin:
Purchases of puts or calls with 9 months or less until expiration must be paid for in full. Writers of uncovered puts or calls must deposit / maintain 100% of the option proceeds* plus 15% of the aggregate contract value (current index level x $100) minus the amount by which the option is out-of-the-money, if any, subject to a minimum for calls of option proceeds* plus 10% of the aggregate contract value and a minimum for puts of option proceeds* plus 10% of the aggregate exercise price amount. (*For calculating maintenance margin, use option current market value instead of option proceeds.) Additional margin may be required pursuant to Exchange Rule 12.10.
http://www.cboe.com/products/indexopts/spx_spec.aspx
See also:
http://wiki.answers.com/Q/Are_requirements_of_margin_in_put_options_writing
Try this out -
1130X100X.15X20= 339K - their last bit is hard to calculate, not sure how that works... either way its a lot of money parked for a 3% or so return..
Margin:
Purchases of puts or calls with 9 months or less until expiration must be paid for in full. Writers of uncovered puts or calls must deposit / maintain 100% of the option proceeds* plus 15% of the aggregate contract value (current index level x $100) minus the amount by which the option is out-of-the-money, if any, subject to a minimum for calls of option proceeds* plus 10% of the aggregate contract value and a minimum for puts of option proceeds* plus 10% of the aggregate exercise price amount. (*For calculating maintenance margin, use option current market value instead of option proceeds.) Additional margin may be required pursuant to Exchange Rule 12.10.
http://www.cboe.com/products/indexopts/spx_spec.aspx
See also:
http://wiki.answers.com/Q/Are_requirements_of_margin_in_put_options_writing