I have read through many posts here and other places and still do not have a definite idea of the best broker for portfolio margin for options strategies. This thread will serve as the reference to those who'd like to open an account with portfolio margin. I am posting a poll here for the three major brokers that offer portfolio margin for 100k-125k. Please explain your experience with your broker regarding portfolio margin. Since portfolio margin requires a high capital commitment, it is uncommon for individuals to have portfolio margin concurrently with more than one broker. So if you can, please provide details of your portfolio along with your experience. If not, just share your experience. I have a portfolio margin account with IB and it is not pretty. I am allowed to make trades (naked short puts on broad based indices) with lot lower margin requirement, only to have the margin requirements almost double overnight without any underlying movement and drop in volatility. Its almost laughable and their customer support said that's how it is supposed to be. My portfolio is heavily concentrated so I must incur that penalty but don't know how much I will need to diversify. There customer service don't know either. Anyway, I am ready to change brokers.