The market is up on the scantest of reasons - Buffet's offer to buy out the municipal bond insurance business of the three largest bond insurers. He won't touch their subprime exposure with a 10 foot pole, and told them that. So, smartly, he wants to put them in a position where regulators pressure the companies to say yes, even though it would be among the WORST BUSINESS DECISIONS EVER MADE - So bad, in fact, that it may represent a breach of duty to shareholders if they say yes. Their muni business is their very essence of being, and is generating positive cash flows. The drain is subprime. If Buffet or anyone else picks them apart, and just buys the muni end, what does that leave them with?