Changpeng Zhao moved fast when Sam Bankman-Fried’s FTX.com was on the brink, offering to take it over and stem any further crypto contagion.

His Binance just as quickly walked away from the beleaguered exchange, leaving the fate of its onetime chief rival uncertain.

“Our hope was to be able to support FTX’s customers to provide liquidity, but the issues are beyond our control or ability to help,” Binance said in a statement.

It became evident in a matter of hours that rescuing FTX would be a tall order for Binance. Its executives found themselves staring into a financial black hole -- a gap between liabilities and assets at FTX that’s probably in the billions, and possibly more than US$6 billion, according to a person familiar with the matter. 

On top of that, U.S. regulators are circling FTX, investigating whether the firm properly handled customer funds, as well as its relationship with other parts of Bankman-Fried’s crypto empire, including his trading house Alameda Research, Bloomberg News reported Wednesday. 

Zhao himself admitted there was no “master plan” to take over FTX.

“As a result of corporate due diligence, as well as the latest news reports regarding mishandled customer funds and alleged U.S. agency investigations, we have decided that we will not pursue the potential acquisition of FTX.com,” Binance said in the statement.

For crypto investors, the stakes are high for what happens next. The downfall of Bankman-Fried, the industry’s 30-year-old wunderkind, has cast doubt about which institutions are safe in the still-loosely regulated market. Bitcoin fell below US$17,000 on Wednesday to a two-year low, joining a widespread selloff in digital assets.

While Bankman-Fried is barely a billionaire anymore, Zhao remains the richest person in crypto, with a fortune estimated at US$16.4 billion by the Bloomberg Billionaires Index. But even Zhao hasn’t been immune to tumbling crypto prices: His net worth peaked at US$97 billion in January.

Coinbase Chief Executive Officer Brian Armstrong said Tuesday in a Bloomberg TV interview that if the deal with Binance fell through, it would likely mean FTX customers would take losses.

“That’s a not a good thing for anybody,” he said.