The $50 Billion question is, did Geithner know? He was head of the NY Federal Reserve bank for five years and Madoff’s activities were a threat to the integrity of the Financial Services Industry, which is a key to the economy of the NY region. Did the SEC inform him of reported cases of large scale fraud?
Working within the Federal Reserve System, the New York Fed implements monetary policy, supervises and regulates financial institutions and helps maintain the nation’s payment systems.emphasis added. The efforts of Harry Markopolos to bring the fraud to the attention of the SEC are known and detailed in the wiki.