The Hang Seng Index added 2.1 per cent to 25,866.49 at the noon trading break, the biggest gain in two weeks. The Hang Seng Tech Index rose 3.1 per cent. On the mainland, the CSI 300 Index gained 1.4 per cent and the Shanghai Composite Index strengthened 0.9 per cent.

Mining firm Zijin Mining surged 6 per cent to HK$24.24 and mainland developer Longfor Group jumped 8.2 per cent to HK$11.60. Search-engine leader Baidu added 6 per cent to HK$90.80, online games provider NetEase climbed 5.4 per cent to HK$216.20. E-commerce giant Alibaba Holding Group climbed 5.9 per cent to HK$124.90 and peer JD.com advanced 4.8 per cent to HK$127.20.

Carmaker Geely Automobile Holdings slipped 1.1 per cent to HK$19.77, while handset components manufacturer BYD Electronic fell 1.4 per cent to HK$38.96.

After Powell hinted at the Jackson Hole symposium on Friday that interest rates could head lower amid a softening jobs market, the S&P 500 rose 1.5 per cent higher, its best gain since May 27, and the tech-heavy Nasdaq Composite added 1.9 per cent.