Shares of Laopu Gold Co. and CMOC Group Ltd. jumped sharply in Hong Kong trading after Hang Seng Indexes Co. added them to the city's benchmark equity gauge. The quarterly review reshuffle brought the Chinese jeweler and miner into the prestigious index, triggering a rally in their stock prices.

The Hang Seng Index inclusion marks a significant milestone for both companies, often leading to increased institutional investment and trading volumes. Index additions typically attract passive funds that track the benchmark, creating upward price pressure. For Laopu Gold, this follows its rapid growth as China's largest gold jewelry retailer by market share.

CMOC, one of the world's largest copper miners, benefits from the index inclusion amid strong commodity prices. The move reflects the Hang Seng's ongoing effort to include more mainland Chinese companies in its flagship index. Both stocks saw substantial gains as investors reacted to the index addition, with trading volumes spiking as funds adjusted their portfolios to reflect the new benchmark composition.