Hong Kong stocks tumbled 637.65 points, or 2.89 percent to close at 21,397.77 points on Tuesday, the first trading day after Chinese Lunar New Year holidays. The benchmark Hang Seng Index traded between 21,609.59 and 21, 388.61. Turnover totaled 75.69 billion HK dollars (about 9.75 billion U.S. dollars). The Hang Seng China Enterprises Index went down 308.71 points, or 3.14 percent, to close at 9,509.65. Three of the four sub-indices lost grounds. The Commerce & Industry sub-index dived 4 percent, the Finance dropped 2.5 percent, the Properties fell 1.51 percent, while the Utilities added 0.16 percent. Banking giant HSBC, which accounts for the largest weighting of the Hang Seng Index, plunged 2.22 percent at 79.15 HK dollars. Its local unit Hang Seng Bank closed down 1.07 percent at 120.20 HK dollars. Bank of East Asia, another Hong Kong's major bank, decreased 1.7 percent at 28.95 HK dollars. Local bourse operator HKEX fell 0.57 percent to 121.20 HK dollars. As for the local developers, Cheung Kong Holding, a powerful HK- based developer owned by billionaire Li Ka-shing, closed flat at 114.90 HK dollars. Henderson Land lost 2.27 percent at 40.85 HK dollars. Sun Hung Kai Properties, another major developer, lost 1. 32 percent to 93.55 HK dollars. Hang Lung Properties moved up 0.46 percent to 21.65 HK dollars. Mainland-based financial stocks tumbled. Bank of China plunged 4.32 percent to 3.21 HK dollars. Bank of Communications lost 2.77 percent to 4.91 HK dollars. China Construction Bank decreased 3.53 percent to 5.20 HK dollars. ICBC fell 3.12 percent to 4.66 HK dollars. As for energy stocks, PetroChina was down 2.4 percent at 7.33 HK dollars. CNOOC sharply fell 5.41 percent to 11.54 HK dollars. Sinopec lost 3.72 percent to 5.95 HK dollars (1 U.S. dollar equals 7.76 HK dollars).