The Securities and Futures Commission (SFC) is investigating nearly 300 suspected cases of insider dealing and market manipulation.
Chairman Anthony Neoh said there had been a surge in alleged incidents earlier in the year, as the blue-chip Hang Seng Index soared to record prices and volumes.
Mr Neoh, who would not disclose how many companies were involved, said investigating the claims would be a leading priority for next year.
'We will reinforce surveillance on stocks with unusual price movements, through our manpower, technology and co-operation with the stock exchange,' Mr Neoh said.
A total of 127 alleged incidents were reported this year, and 169 had been carried forward from previous years.
Since January, there have been five insider-dealing cases heard by the Insider Dealing Tribunal, including the conviction of the founder of property developer Hong Kong Parkview Hwang Chou-shiuan.
