Hong Kong stocks jumped to a record high Monday after Beijing allowed mainland banks to invest in overseas stocks, the Wall Street Journal reported. The Hang Seng Index surged 511.03 points to close at 20979.29 on its busiest trading day in history. The Hang Seng China Enterprises Index, surged 5.4% to 10948.72. China issued new rules on Friday allowing commercial banks to invest as much as half of the funds in their qualified domestic institutional investors program, QDII, offshore making US$7.25 billion available for such investment in one stroke. About half of the US$1.9 trillion in market capitalization in Hong Kong comes from China companies, compared to 40% a year ago. The sharp hike in Hong Kong stocks Monday did not take away from the continued bull run of the A-share market. China's Shanghai Composite Index closed up 0.6% to close at 4046.