As an example, John Paulson made billions betting against sub-prime mortgage paper, speculating that the housing market would self-destruct. He was right and made billions, but did that have a positive effect on the market? No. His insight, which arguably was important to help the US manage the biggest financial crisis is 80 years, had no effect, except to make him rich. If Wall Street really worked as the commentators want us to believe, his insight into the housing market should have helped avoid the crisis, but it didn't. It's just gambling, unrelated to the real world, except to the extent that if the Wall Street gamblers lose too many billions, the taxpayers will bail them out. Ironically, the WSJ article about Paulson says that he he has hired Alan Greenspan, who aided Paulson's strategy by keeping interest rates abnormally low for too long. That's more a criticism of Greenspan than Paulson. But they are clearly too cozy.