Harry M. Markopolos (born October 22, 1956) is an American former securities industry executive and an independent forensic accounting and financial fraud investigator. He discovered evidence over nine years suggesting that Bernard Madoff's wealth management business, Bernard L. Madoff Investment Securities LLC, was actually a massive Ponzi scheme. In 2000, 2001, and 2005, Markopolos alerted the U.S. Securities and Exchange Commission (SEC) of the fraud, supplying supporting documents, but each time, the SEC ignored him or only gave his evidence a cursory investigation.
Madoff was finally uncovered as a fraud in December 2008, when his sons contacted the Federal Bureau of Investigation. After admitting to operating the largest private Ponzi scheme in history, Madoff was sentenced in 2009 to 150 years in prison.
In 2010, Markopolos' book on uncovering the Madoff fraud, No One Would Listen: A True Financial Thriller, was published. It also included an introduction written by a member of his legal team, Gaytri Kachroo.
Markopolos has scathingly criticized the SEC for both failing to discover the Madoff fraud despite repeated tips, and for failing to investigate properly the larger companies it supervised. He described the private moments he had with victims of the Madoff fraud as: "Heartfelt, gut-wrenching things. People trying to commit suicide or losing loved ones who've died of heartbreak.