Sam Bankman-Fried woke up Monday still a billionaire, even as his cryptocurrency empire was starting to unravel.  By Friday, his fortune was completely gone.   

  Bankman-Fried was worth about $16 billion at the start of the week, according to Bloomberg net worth calculations.  But as his crypto exchange, FTX, collapsed, the value of his assets plummeted to zero in what Bloomberg called “one of the greatest wealth catastrophes in history.”   

  FTX announced Friday that it has filed for bankruptcy and Bankman-Fried, known as SBF, has stepped down as chief executive.   

  The 30-year-old entrepreneur’s net worth, which was largely tied to digital assets, peaked at around $26 billion this spring.  Over the summer, as cryptocurrency prices plummeted, Bankman-Fried emerged as a white knight for the industry, using the FTX exchange and its sister hedge fund, Alameda, to secure credit lines to crypto companies like BlockFi and Voyager that were in danger of collapsing.   

  He told Reuters in July that he and FTX still had “a few billion” left to prop up other companies and help stabilize the industry.   

  Bankman-Fried owns about 70% of FTX’s US business, which the index now estimates to be essentially worthless.  His stake in online brokerage Robinhood, previously valued at more than $500 million, was removed from Bloomberg’s calculations after news reports said the stake was held through Alameda and may have been used as collateral for loans.   

  As a follower of “effective altruism,” Bankman-Fried tried to make as much money as possible to give away.  But the fate of his philanthropic efforts is now in doubt.   

  On Thursday, the entire staff of the FTX Future Fund, which it says has committed $160 million in grants, publicly resigned.  In a statement, the five-person group wrote that they “have fundamental questions about the legality and integrity of the business activities funded by the FTX Foundation and the Future Fund.”