China's securities regulator issued new rules on share trading by company executives, the South China Morning Post reported. The new rules, which took effect April 5, are intended to "strengthen management of the stock holdings and transaction by board members and senior managers of the listed firms" as mainland bourses hit record highs. The mainland market has gained almost 25% this year as new mutual funds continue to buy A-shares, the newspaper reported. The China Securities Regulatory Commission limited trading by senior managers in one year to 25% of the company shares they held in the previous year and banned them from trading within a year of a firm's listing or six months after leaving the company. The CSRC also forbade buying or selling 30 days before regular reports or 10 days before performance forecasts.