On June 8, Chalco (02600.HK) fell 8% in regular trading, trading at HK$10.24/share, with trading volume of HK$398 million. The sharp decline came precisely on the effective date of the company's formal inclusion into the Hang Seng Index constituent stocks.

On the news front, the stock had surged limit-up on May 26 on dual catalysts — Guinea's planned June implementation of bauxite export controls and the HSI inclusion announcement. Since then, the stock has been under sustained selling pressure as institutional and northbound funds engaged in concentrated profit-taking, exhibiting a classic buy-the-rumor-sell-the-fact pattern. Main capital has recorded continuous net outflows over multiple sessions, with approximately RMB 900 million flowing out over the prior five trading days.

The broader aluminum sector remains under pressure, with peers China Hongqiao down 1.73%, Chuangxin Industrial down 2.16%, Nanshan Aluminum International down 3.09%, and Rusal down 3.65%. Additionally, the company had already cut aluminum ingot spot prices across regions on June 4, while concerns over rising alumina costs squeezing margins persist, compounding selling momentum.

(The above content is based on publicly available market information, generated by a program or algorithm, and is intended solely as a stock movement alert. It does not constitute investment advice or a basis for trading decisions.)