Officers from the Securities and Futures Commission and the police raided 47 premises on Wednesday and arrested the eight men and one woman aged between 25 and 62.
Six senior managers of the listed companies and a financial analyst are among the suspects.
The Monetary Authority of Singapore also arrested a woman in connection with the case, during a joint-operation with Hong Kong.
The authorities alleged there had been a “ramp and dump” scam, where the stocks of the three listed companies were hyped up by up to 600 percent, while social media posts urged people to buy them.
Some of those involved in the alleged scam then sold their holdings at inflated prices and pocketed HK$160 million, leaving other investors out of pocket when the prices tumbled, police said.
“We have very sophisticated surveillance detection equipment that monitors how stock moves. A lot of time you can see an increase in value but there’s no real news about why it is increasing in value, there’s no change in its fundamentals,” said Thomas Atkinson, the executive director of the SFC’s enforcement division.
“A lot of time it’s increasing in value because people are simply trading the stock back among themselves to create the appearance of volumes, while other people will trade in to that.”
SFC officials said they could not estimate how many victims there had been, saying it could run into hundreds, and it might take years for them to get their money back.
Authorities froze assets worth HK$47 million and seized about HK$2 million cash in their operation.
