Group 1 - The Hang Seng Index (HSI) rose by 27.8% in 2025, marking its best performance since 2017, following a 17.7% increase in 2024 [1] - The rise in the HSI was driven by record capital inflows from the Hong Kong Stock Connect, optimism about the future of artificial intelligence, and interest rate cuts [1] - The HSI outperformed two other flagship indices: the Hang Seng China Enterprises Index (up 22.3%) and the Hang Seng Tech Index (up 23.5%) [1] Group 2 - The Hang Seng Composite Index (HSCI) increased by 31.0% in 2025, with mid-cap stocks leading the gains at 31.6%, followed by large-cap stocks at 30.8% and small-cap stocks at 28.8% [2] - Among industry indices in the HSCI, the materials sector had the best performance, rising by 161.3%, while utilities had the worst performance with a 5.7% increase [2] - The Hang Seng High Dividend Yield 30 Index led the high dividend indices with a rise of 38.1% in 2025 [2] Group 3 - The Hang Seng Climate Change 1.5°C Target Index performed well, with an annual increase of 31.2% [3]

Group 1 - The Hang Seng Index Company announced adjustments to the calculation methods of several indices, including the Hang Seng Hong Kong Stock Connect Innovative Drug Index, Hang Seng Innovative Drug Index, Hang Seng Biotechnology Index, and Hang Seng Hong Kong-US Biotechnology Index [1] - The adjustments aim to enhance the focus on pure innovative drug companies by excluding companies primarily engaged in the CXO industry, which includes Contract Research Organizations (CRO), Contract Manufacturing Organizations (CMO), and Contract Development and Manufacturing Organizations (CDMO) [2][4] - The changes will result in a more concentrated index composition, with the top five constituents of the Hang Seng Hong Kong Stock Connect Innovative Drug Index shifting to companies like Innovent Biologics, BeiGene, and others, while the previous weight of excluded companies was approximately 18.1% [3] Group 2 - The Hang Seng Biotechnology Index will see a reduction in the number of constituents from 50 to a fixed number of 30, along with new trading qualification requirements under the Stock Connect program [6] - The Hang Seng Hong Kong-US Biotechnology Index will also reduce its constituent count from 60 to a fixed number of 40, indicating a significant decrease in the number of stocks included [9] - The adjustments to the indices will take effect on June 30, 2025, with the changes in constituent stocks implemented on September 8, 2025 [9]

Group 1 - The Hang Seng Biotechnology Index will undergo updates in its calculation methodology, including new requirements for the Stock Connect trading eligibility and modifications to the selection criteria [1] - The number of constituent stocks in the Hang Seng Biotechnology Index will be fixed at 30 [1] - The listing history requirement will be removed, and a rapid inclusion mechanism will be introduced [1] Group 2 - The Hang Seng Hong Kong-US Biotechnology Index will also see updates, with the number of constituent stocks fixed at 40 [1]