Blackmon, the New York-based auction house that has been dealing in blackcoins for more than two decades, has gone dark.
It will not reopen until a new, more stringent regulatory framework is in place, according to an announcement on Tuesday by the company.
Blackmon will shut down on April 20, according a company spokesman.
Its shares had been trading near $8, but they were down more than 20% to close at $5.20.
It was one of the biggest bidders in the last wave of the digital currency boom.
Blackcoin was a pioneer in the bitcoin craze and its founder, Charlie Lee, has since gone on to become one of its biggest fans.
It has a market capitalization of $3.2 billion.
The announcement said that Blackmon’s new regulatory framework will be announced in May.
The regulator will have to be notified of any new developments and the company has not yet responded to the announcement.