A former city commercial bank executive has been caught with his hands in the insider trading cookie jar, landing him an 18 million yuan ($2.7 million) fine, the biggest levied for such violations so far this year, the state securities regulator said Friday.

Li Fu, a former president of Guangdong-based Nanyue Bank, along with his wife, were accused by the China Securities Regulatory Commission (CSRC) of trading using insider information from steel wire producer Ningxia Xinri Hengli in 2015. The pair netted 4.5 million yuan in illegal profits from the transactions, the CSRC said.

Li is an acquaintance of Xinri Hengli’s controlling shareholder Yu Jianming, and has helped Yu’s companies to obtain loans from Nanyue Bank, according to the CSRC. Investigators found that the Li couple’s stock transactions were highly correlated to Li’s contact with Yu.

The securities regulator has stepped up its fight against insider trading since last year as China’s stock market entered bear territory. Some 87 insider trading cases were filed by the regulator last year. Since the beginning of this year, the CSRC has handed out 10 penalties for the illegal practice of making trades using insider information.

Related: Securities Regulator Handed Out Record Penalties in 2018