His BAC bet seemed to be a reversion to his hedge-fund cowboy days (read the early partnership letters) at a time when he is no longer the only cowboy in town.
Combined with his big position in Wells Fargo, his deeply underwater warrants in Goldman and the General Electric warrants and you can see a concentration in an area with some of the most opaque balance sheets in the world.
In particular, note the double bottoms in the first two charts. A hold at these levels would be a nice entry point whereas cracking that support could set up 30 to 50% declines from here.
I'm going to flesh this out next week but for now here's some food for thought (three month charts):
Bank of America