A court-appointed trustee in New York has mailed out $2.5 billion in checks to victims of Bernard Madoff's massive fraud.

Irving Picard announced the distribution on Thursday. He said it means that he's so far satisfied nearly half of all valid claims made by the disgraced financier's burned clients.

Picard has estimated that thousands of investors lost $17.3 billion in the decades-long fraud. He says he's recovered about $9.1 billion since he was appointed following Madoff's arrest in 2008.

Madoff pleaded guilty in 2009 to charges that he orchestrated the largest Ponzi scheme in history. He's serving a 150-year prison term.