Sam Bankman-Fried, co-founder at crypto exchange FTX, tweeted Friday that he was “shocked to see things unravel the way they did,” after he quit as chief executive and the company and its related entities filed for bankruptcy.

See: Sam Bankman-Fried resigns as CEO of FTX as cryptocurrency exchange files for Chapter 11 U.S. bankruptcy

The bankruptcy “doesn’t necessarily have to mean the end for the companies or their ability to provide value and funds to their customers chiefly, and can be consistent with other routes,” Bankman-Fried tweeted Friday.

Bankman-Fried has seen his net worth plunge to almost zero from $16 billion in less than a week, according to Bloomberg Billionaires index.

FTX was once the third largest cryptocurrency exchange by trading volume. Bitcoin BTCUSD, -6.27% fell 3.4% Friday to around $16,838, hovering at around a two-year low, according to the CoinDesk data.

A representative at FTX didn’t respond to a request seeking comment.