(Yicai Global) Sept. 22 -- The China Securities Regulatory Commission has punished inside traders on the security, futures and stock markets. Last year was the first in which the regulator handed out penalties worth more than USD15.18 million (CNY100 million) for insider trading cases, containing such activities to a certain degree.

Special law enforcement officers clamping down on such activities have investigated and handled 18 major cases, mainly in the areas of mergers and acquisitions as well as ownership structure changes, People's Daily learned from the China Securities Regulatory Commission yesterday.

Despite a decline in insider trading in recent years, more leaks of inside information that could influence buying and selling patterns took place.

With the diversification of communication channels and the popularization of online social networks, rat traders have become more secretive and investigating and collecting evidence has become more difficult.

Rat traders acting on information themselves accounted for 31 percent of such investigated and registered activities last year, while insiders' relatives, friends, classmates and business partners made up 69 percent.

The China Securities Regulatory Commission's will continue cracking down on insider trading to guarantee trade markets are healthy and stable.