Hong Kong stocks build on gains at open

The Hang Seng Index climbed 1.74 percent, or 540.09 points, to 31,536.30.

And the benchmark Shanghai Composite Index rose 0.36 percent, or 12.04 points, to 3,319.21, while the Shenzhen Composite Index, which tracks stocks on China's second exchange, was up 0.53 percent, or 9.96 points, to 1,895.34.