Bittrex, one of the largest crypto exchanges in the U.S., has filed for Chapter 11 bankruptcy protection for its American operations following accusations of operating an unregistered securities exchange by the Securities and Exchange Commission (SEC) three weeks prior.

According to the filing, Bittrex has assets and liabilities each estimated to be worth between $500 million and $1 billion, and has over 100,000 creditors.

Bittrex Global, its Liechtenstein-based offshore operations, are unaffected by the bankruptcy filing. The company announced that it will reopen customer accounts to allow them to withdraw funds, and crypto assets of U.S. customers who did not withdraw funds before April 30 remain safe and secure.

The SEC accused Bittrex of selling and promoting unregistered securities. However, Bittrex denied the allegations, stating that the assets it offered were not securities. The U.S. Congress has yet to officially classify crypto assets as securities.