problem is biiger than what looks like
investment banks are highly leavaged. Given the run-up of stock market, one has to ask how much leavage these investment banks have used to chase market.
LBOs use 3 to 1 leavage.
So, what looks like $50B is actually much bigger than $50 B. Plus, there might be chain reaction.
This migh explain why BSC is so afraid of MER auction its holdings.