Try shocking your portfolio the way the OCC does(stocks). Equities +\- 15% narrow indexes +\- 10% broad based indexes +6%\-8% do it by underlying and add up the shocks. Then determine if there were a one day move of that amount, what is the most your willing to lose.
Nah, thats not really what im looking for because it doesn't include the cost of leverage and buying power leverage gives you.
OK, now I understand. If you have a retail account, the interest can range today from around 1.5% to 7%. Only you will know what you pay.