Mainland Chinese and Hong Kong stocks advanced on Wednesday, tracking overnight gains on Wall Street, as renewed optimism over a potential resumption of US-Iran talks eased geopolitical concerns and dragged oil prices lower. Hong Kong’s Hang Seng Index rose 1 per cent to 26,136.71 as of 9.50am local time, extending a 0.8 per cent gain on Tuesday. On the mainland, all major benchmarks traded higher