The fall of crypto poster boy Sam Bankman-Fried is complete: The ex-billionaire resigned from his exchange FTX on Friday, as the company declared bankruptcy.

The 30-year-old was once hailed as a pioneer of responsible crypto investing, and trust in FTX helped make it the third-largest exchange in the world.

Now Bankman-Fried is slinking off in disgrace, leaving little but questions and investors who will have to fight for what’s left through the bankruptcy court system.

In a Twitter thread expressing his “shock” over how things unraveled, Bankman-Fried said he was “really sorry, again, that we ended up here.”

“Hopefully things can find a way to recover,” he wrote. “Hopefully this can bring some amount of transparency, trust, and governance to them. Ultimately hopefully it can be better for customers.”

John J. Ray, who is replacing Bankman-Fried as CEO, said in a statement that filing for bankruptcy is “appropriate to provide the FTX Group the opportunity to assess its situation and develop a process to maximize recoveries for stakeholders.”

“The FTX Group has valuable assets that can only be effectively administered in an organized, joint process. I want to ensure every employee, customer, creditor, contact party, stockholder, investor, governmental authority and other stakeholder that we are going to conduct this effort with diligence, thoroughness, and transparency.

“Stake-holders should understand that events have been fast-moving and the new team is engaged only recently. Stakeholders should review the materials filed on the docket of the proceedings over the coming days for more information.”

Fast-moving is something of an understatement for the speed with which FTX collapsed.

The spiral began last week when crypto news site Coindesk published a story that raised questions about the solvency of Bankman-Fried’s companies, reporting his trading group, Alameda Research, had most of its assets tied up in a risky token issued by another one of his companies.

Days later came the shock announcement by SBF—as he is known in the industry—that he was selling to rival Binance. But Binance swiftly pulled out of the bailout, suggesting it could not save FTX, and Bankman-Fried could do little more than beg stakeholders for forgiveness.

“I’m sorry. That’s the biggest thing,” he wrote in a 22-tweet thread on Thursday. “I fucked up, and should have done better.”

“Right now, my #1 priority—by far—is doing right by users,” he added. “And I’m going to do everything I can to do that. To take responsibility, and do what I can.”

Bankman-Fried reportedly lost approximately 94 percent of an approximately $15 billion personal fortune following the collapse—which he chalked up to underestimating his users’ margin and a rush of withdrawals, essentially a run on the bank.

The Wall Street Journal reported that the Securities and Exchange Commission and the Justice Department are eyeing the company’s implosion.