I've been with IB for a long time, but recently they raising VIX related margin really pissed me off. The ratio for VXX went up insanely to 230%. Under such margin ratio, it's impossible for my strategy to make money.
I'm considering switch broker seriously. I usually short VIX ETF, holding short positions for some time. So the shorting interest is important to me. But as I know most brokers using fixed rate for short interest, like 6% or 8% which is much higher than IB's market shorting rates.
So I'm looking for a broke that 1 have portfolio margin, 2 using the similar shorting interest rate like IB. I went through some post in this forum. It looks that many people use IB so it does have it advantages. If you know other brokers qualify my requirements or you're representing a broker and want to introduce it to me, please give my some suggestions.