The US Securities and Exchanges Commission (SEC) has halted trading in Cynk Technology after its shares increased in value by 23,000 per cent in the last month.
The little-known social networking firm is registered in Nevada with an office in Belize City, Belize but has no revenue and just one employee.
The SEC which suspended trading until 24 July explained that the shares in Cynk were trading in an "over the counter exchange" with little regulation.
"It appears to the SEC that the public interest and the protection of investors require a suspension of trading in the securities of Cynk Technology Corp ("Cynk") because of concerns regarding the accuracy and adequacy of information in the marketplace and potentially manipulative transactions in Cynk's common stock," the SEC stated in its order suspending trading in the company.
Subsequently, the Financial Industry Regulation Authority (Finra), another US regulator, has also halted trading on Cynk under its "extroadinary event halt" code.
The company's shares rocketed in value from six cents in early June to $13.90 (£8.11) last week, giving the firm a value of almost $4 billion (£1.8 billion).
Cynk's primary website, introbiz.com bills itself as a marketplace where users "may both buy and sell the ability to socially connect to individuals such as celebrities, business owners, and talented IT professionals."