Bloomberg’s Billionaires Index lowered its estimate of cryptocurrency exchange Binance’s earnings by 38 per cent after it became known that trading volumes on it have declined this year. As a result, the fortune of Binance founder Changpeng Zhao, known as CZ, fell by $11.9bn to $17.2bn.

CZ, 46, played a role in the events that landed BankmanFried in federal court. In November, the Binance founder announced the liquidation of a token linked to FTX after it was revealed that Bankman-Fried’s hedge fund Alameda Research also held a large position in the token. Some FTX customers rushed to withdraw their money, and the exchange was unable to handle the surge in withdrawals. Less than a week later, it declared bankruptcy.

As a result, Binance-Fried’s own fortune, which peaked at $26bn in March last year, has fallen.

The index calculates Binance’s revenue based on spot and derivatives trading data from crypto-tracking services Coingecko and Coinpaprika.

At the beginning of the year, Binance captured a large market share, reaching 62 per cent of total cryptocurrency exchange trading volume in the first quarter, thanks to a zero commission promotion for popular trading pairs. After the promotion ended, Binance’s share fell to 51% by the end of the third quarter, according to research firm CCData.

In recent months, the cryptocurrency exchange has found itself increasingly isolated from the traditional financial system.

The Securities and Exchange Commission sued Binance in June, and earlier this year the Commodity Futures Trading Commission accused it of failing to comply with rules allowing U.S. users to access Binance. Regulatory officials allege that the company failed to have adequate money laundering controls, inflated trading volumes and mishandled customer funds. Binance disputes these allegations and is fighting them in court.