Chinese regulators are intensifying their sweeping crackdown on corporate insiders, slapping top executives with severe fines, criminal sentences and market bans as Beijing seeks to restore confidence in the country’s embattled stock markets. More than two-thirds of the cases involved suspected violations of information-disclosure rules; the rest spanned short-swing trading, illegal share reductions, market manipulation and insider trading. Regulatory inquiries into 43 listed companies through June affected more than 2.5 million retail investor accounts, domestic media reported. Shares in most of the targeted firms plunged by their daily limit on the first trading day following each disclosure. In April, Jiangsu-based environmental firm Pengyao Environmental Protection disclosed that Wang Hongchun, one of its actual controllers, had been sentenced to a suspended 2.5-year prison term for insider trading, fined 10.6 million yuan (US$1.57 million) and ordered to forfeit 5.26 million yuan in illegal gains.