In March 2009, Madoff pleaded guilty to 11 federal felonies and admitted to turning his wealth management business into a massive Ponzi scheme. Thousands of investors lost billions of dollars. Madoff said he began the Ponzi scheme in the early 1990s. However, federal investigators believe the fraud began as early as the 1970s. The people who are hunting for the missing money believe the investment operation may never have been legitimate. The amount missing from client accounts, including fabricated gains, was almost $65 billion. The court-appointed trustee estimated actual losses to investors of $18 billion. On June 29, 2009, he was sentenced to 150 years in prison, the maximum allowed.