The Shanghai Stock Exchange yesterday halted trading in China Merchants Bank warrants three times after uncovering questionable trades.
Two accounts at a United Securities outlet in Shenzhen were suspended from trading on possible price manipulation, the exchange said. It did not identify the owners of the suspended accounts.
Yesterday's suspension on CMB warrants was the second time in as many months. On June 12, trading was halted for half an hour.
The exchange said the two accounts were suspected of 'churning', or price-rigging, and warned investors of risks in the derivative product. The CMB warrants closed at 50 fen yesterday, up 242 per cent.
'The exchange hopes investors will understand the risks by halting trading,' said Wei Wei, a trader at West China Securities. 'This is a signal to remind ignorant investors not to chase short-term gains on the warrant.'
The suspension highlights problems in the mainland's warrant market, the world's largest by sales, which is plagued by rampant trading and runaway investment.