can you explain how you would get a margin call at $84, while shorting at $42.5? that would imply almost 100% in the hole, (losing $42 on a $42.5 investment) which really means you bought at cash, and therefore you would not get a margin call at all.
I made about half that much on RMBS recently going the other way. I bought in near $11, bought 50K shares and have sold calls on all of them at an average $4 or so per share, $400 X 500 contracts. I am taking less risk than you as my sold (short) calls give me a sort of a hedge.
I found RMBS on CoveredCalls.com, bought 4 or 5 of their best deals lately like ONXX and EMIS and all together I am in the $1 Million+ area of gains for the past few months too. I started trading call/write deals in July with $400K and am now approaching $1.5 Million. Before that I bought and held stogy Preferred Stocks, Boy, am I glad I switched strategies!
that is so courageous and brilliant move! Some of us who knew and believed that RMBS was way over valued and were shocked so many longs were day dreaming about it was heading to $70 to $80. Once again, my deepest respect for your courage to make the move for what you believed in and researched regardless a lot of name callings back then by the longs. Congrat!