(Yicai) July 7 -- The Shenzhen Stock Exchange has barred several investors from trading after a crass online post seemingly drove up the share price of vocational training provider Offcn Education, sending it nearly 30 percent higher over the past week.

The bourse has been closely monitoring trading in Offcn Education’s stock and has suspended the trading privileges of the investors involved, whose actions led to abnormal trading behavior that disrupted the normal market order, it said in a statement released late yesterday. The exchange also urged investors to be mindful of investment risks and trade prudently in compliance with regulations.

The move followed a social media post by an investor saying that if Offcn Education's share price failed to rise 20-fold within a year, she would carry out a vulgar and inappropriate pledge. This was quickly reposted by other investors, sending the sensational wager viral and attracting widespread attention.

Offcn Education's shares [SHE: 002607], which had languished for months, subsequently climbed, hitting their daily trading limit on two of the following four trading days. The stock added a further 8.1 percent today, finishing at CNY2.26 (33 US cents).

The episode has renewed concerns over social media-driven speculation in China's stock market. Some investors said the online stunt may have been intended to fuel speculative buying to enable shareholders to sell at inflated prices.

Offcn Education issued a risk warning last night, saying its business operations remain normal and that there have been no material changes to its operating environment and that none are expected. There are no undisclosed matters that should have been reported to investors, it added.

The Beijing-based company’s profit plunged 73 percent last year to CNY48.9 million (USD7.2 million), while revenue tumbled 15 percent to CNY2.2 billion (USD312 million).

Editor: Kim Taylor