The Singapore Police and the Monetary Authority have raided several brokerages in the city this week as the Singapore Stock Exchange has reported manipulation and insider trading about some of them.
The MAS said on Friday that the Commercial Affairs Department (CAD) of the Singapore Police and the MAS are together investigating broking firms for possible breaches of the Securities and Futures Act.
The MAS said they have obtained documents and items from several broking firms and trading representatives.
The Singapore Exchange also said on Friday that "in the January to March quarter, we referred nine cases to MAS of which three were related to insider trading and six to market manipulation.".
According to a report by the Business Times, DBS Vickers, Maybank Kim Eng, OCBC Securities and Philip Securities are among the broking firms raided on Monday.
"The Monetary Authority of Singapore and the Commercial Affairs Department of the Singapore Police Force are jointly investigating possible contraventions of the Securities and Futures Act (Cap. 289) and have obtained documents and items from several broking firms and trading representatives. As investigations are ongoing, we are not able to provide further information" said an MAS spokesman on Friday.
The Securities and Futures Act also governs institutions' and individuals' activities in the public markets.
Some traders are of an opinion that incidents like the October 2013 penny stock crash may be prompting the authorities to step up monitoring and enforcement.
"In recent months there were a number of counters collapsing spectacularly and obviously people have gotten hurt," a trader was quoted as saying in a Straits Times report.
"In most cases the underlying company fundamentals have changed little. This is perhaps suggesting that the counters have been played up."