China saw fewer "rat trading" cases in 2017 as financial regulators stepped up supervision to curb market irregularities.
Rat trading is when fund managers use their personal accounts to buy shares before the share price is boosted by large purchases from their funds, therefore "front-running" their clients to earn profit.
The China Securities Regulatory Commission (CSRC) said that it placed 13 rat trading cases on file in 2017, down 60 percent from the previous year.
The reduction came after strengthened financial supervision last year, with regulators maintaining a tough stance on inspections and law enforcement.
The CSRC dealt with 90 major cases of market violations last year, double that of 2016.
Irregularities mainly involved misrepresentation, market rigging and insider trading, the regulator said, adding that it placed 101 new insider trading cases on file, accounting for 32 percent of the total.