Alan Greenspan, five-term chairman of the Federal Reserve, blasted FTX’s downfall as “purely fraud” in a year-end interview with Advisors Capital Management.

Greenspan’s assessment of the bankrupt cryptocurrency exchange runs counter to FTX founder Sam Bankman-Fried’s assertion that his $32 billion empire’s collapse was possibly due to inexperience, negligence or sloppy bookkeeping, as the New York Post reports.

“Based on the information that has come to light so far, the collapse of FTX was not a result of lax risk management, inadequate accounting procedures, or some feature inherent to crypto—it was purely fraud,” Greenspan says.

U.S. authorities have accused Bankman-Fried of using customer funds to bankroll his lavish lifestyle in the Bahamas; fund risky ventures; prop up his hedge fund Alameda Research; and become a major Washington, D.C., political donor to Democrats.

On Tuesday at his arraignment in Manhattan, SBF pleaded not guilty to eight federal charges that carry up to 115 years in prison.

As chairman of the Fed between 1987 and 2006, 96-year-old Greenspan served under four presidencies, beginning with Ronald Reagan and ending with George W. Bush.

Greenspan also said he is wary of cryptocurrencies as a whole: “With respect to the wider crypto universe—I view the asset class as too dependent on the ‘greater fool theory’ to be a desirable investment,” he said.

The “greater fool theory” is one based on overpriced assets continuing to rise due to other “fools” willing to jump in. In June, billionaire Bill Gates also referred to cryptocurrencies and non-fungible tokens (NFTs) as “100%” based on greater fool theories.

JPMorgan Chase CEO Jamie Dimon is also an outspoken critic of cryptocurrency, along with Oracle of Omaha Warren Buffett and his colleague Charlie Munger, vice chairman of Buffett’s firm Berkshire Hathaway.