Lock-up shares worth 50 billion yuan (8.2 billion U.S. dollars) will become eligible for trade this week on the Chinese mainland. The volume is slightly less than the 50.8 billion yuan seen from Dec. 30, 2013 to Jan. 3, 2014, according to information from the Shanghai and Shenzhen stock exchanges. Altogether, 24 listed companies on the two stock exchanges will see their lock-up shares released to capital markets this week. Under the mainland's market rules, major shareholders of non-tradable stocks are subject to one or two years of lock-up before they are permitted to trade. Of all the companies with non-tradable shares becoming tradable this week, China Hainan Rubber Industry Group Co., Ltd. has the most -- shares worth 20.8 billion yuan.