Supervision of the stock market is being tightened, Director of the State Securities Commission (SSC)'s Inspection Department Nguyen The Tho told Dau Tu Chung Khoan (Securities Investment) newspaper.

In the first 10 months of this year, the commission analysed 70 stocks with unusual transactions and examined some cases further.

In the Ho Chi Minh City Stock Exchange, three cases of securities market manipulation were handled this year, in comparison to only one or two in previous years, Tho said.

According to current regulations, stocks found with unusual transactions are reported to the SSC for analysis of cash flow and collusion between investors.

However, Tho said these tasks remained difficult because they required the co-operation of the banks and other relevant organisations.

According to Le Thi Tuyet Hang, director of the Transaction Supervision Department of the Ho Chi Minh City Stock Exchange, in some countries with developed stock markets, stock exchanges would warn investors about unusual transactions.

In the Republic of Korea, stock exchanges publicly announced codes with unusual fluctuations, such as those continuously traded by one or two accounts or those frequently fluctuating sharply, Hang said.-VNA