My two favorite fraudulent shorts--MBIA and Ambac--fell again on Friday, MBIA to a disastrous new low. Once during the last twelve months it was $76.02. On Friday, it was actually $18.43 and closed at $18.74. Triple A ratings, shmiple A ratings from the agencies (Moody's, S & P, Fitch) didn't and couldn't stop the slide. MBIA has announced a billion dollar investment from Warburg Pincus, and there are two other money managers who have public confidence in the company. Still, it goes from horrible to more horrible. To...MBIA had let slip a few weeks ago that Warren Buffett had an interest in this slippery bond insurer, an interest that would have undercut his spotlessly honorable investment record. When the Buffet rumor became public the stock crawled up a few bucks.Well, now Buffett has shown exactly what his interest is: he is starting a competing firm. According to Friday's Wall Street Journal it will be called Berkshire Hathaway Assurance Company, and its business will be to guarantee bonds that governments use to finance public infrastructure, exactly MBIA's (and Ambac's) business. That's the news that drove the stock price down nearly 16%. How much further down it goes nobody knows. But I have my suspicions.