Only after the housing bubble began to deflate did Merrill Lynch and other banks begin to clearly divulge the many billions of dollars of troubled securities that were linked to them, reported the New York Times' blog "Deal Book." In the third quarter of 2007, for instance, Merrill reported that its potential exposure to certain subprime investments was $15.2 billion. Three months later, it said that exposure was actually $46 billion. At the time, Merrill said it had initially excluded the difference because it thought it had protected itself with various hedges. But many of those hedges later failed. "It’s like the parable of the blind man and the elephant: You had some people feeling the trunk and some the legs, and there was nobody putting it all together," said Gary Witt, a former managing director at Moody’s who now teaches at Temple's Fox School of Business.