Bittrex Inc. has filed for Chapter 11 bankruptcy protection for its US-based operations, three weeks after the Securities and Exchange Commission (SEC) accused it of operating an unregistered securities exchange.

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

However, the company stated that its Liechtenstein-based offshore operations, Bittrex Global, were not affected. Two other entities, Bittrex Malta Ltd. and Bittrex Malta Holdings Ltd., also filed for bankruptcy protection in the US.

The SEC alleged that Bittrex and its executives were promoting and selling unregistered securities, to which Bittrex denied.