Chinese brokers have welcomed the freeze on shares held by senior managers in their own firms, saying it will help curb insider trading and provide a fairer trading environment for investors. The Shanghai Stock Exchange announced the freeze on August 1 and the Shenzhen market promptly followed suit, with managers only allowed to trade their shares once they had left their posts. Under China's 1994 company law senior managers are banned from trading shares in their own listed companies, but in practice the law has been largely ignored.