The Hong Kong Futures Exchange says an investigation of unusual trading movements in the futures market last Thursday has shown no evidence of wrong-doing. 'We have done an investigation and found that there was no irregularity,' an exchange spokesman said. Traders were aghast last Thursday when the June index future contract opened the session at 9,000 points, more than 1,000 points higher than Wednesday's close, with the surge not supported by gains in the underlying cash market. The index future quickly retreated with relatively few transactions completed until the market stabilised around the 8,500-point level. The opening bids prompted rumours of market rigging and talks of massive losses incurred by a number of broking houses. 'It was just a horrendous day, every broker in town had one of their worst mornings ever,' one broker said.