To further enhance the Shanghai Stock Exchange (SSE) index system and provide a more comprehensive view of the overall performance of small and mid-cap listed companies in the SSE market, the SSE and China Securities Index Company (CSI) announced upgraded methodology for SSE 380 Index on May 30, 2025 and the launch of the new SSE 580 Index. The revised SSE 380 Index will officially take effect on June 16, 2025, with real-time data for SSE 580 Index available on the same day.

Along with the rapid growth of China's macro economy and continued changes to its industrial structure, the number of listed companies and market capitalization on the SSE keeps expanding, leading to rising investor demand for indices and thus the growing need to enhance the SSE broad-based index system. On the one hand, the SSE 380 Index was introduced over a decade ago. As the capital market evolves, its methodology starts to show certain limitations in representativeness, rule consistency, and sample stability. On the other hand, the market capitalization of more than 60% of SSE-listed companies is below 10 billion yuan, while the SSE 180 and SSE 380 indices primarily cover large and mid-cap companies, representing only about 25% of the market. This creates a gap in indices that accurately represent small-cap companies.

Based on the above considerations, the SSE and CSI optimized the SSE 380 Index and launched the SSE 580 Index. The SSE 380 and SSE 580 are positioned as "mid-cap" and "small-cap" indices for the SSE. They adopt a mainstream broad-based index framework that incorporates liquidity screening and total market capitalization selection. Additionally, ESG screening criteria are introduced to highlight the quality of the selected constituents. The revised SSE 380 Index shows improved representativeness, with constituents’ market capitalization covering 14.7% of the total, an increase of approximately 1 percentage point compared to before the optimization. The industry distribution is improved, with a balanced weight between traditional industries and emerging industries. The stability of the index is enhanced, with an average constituent turnover rate of 13.8% over the past three years, down 7.6 percentage points from before the optimization. SSE 580 Index attributes approximately 30% of its weight to companies from the SSE STAR Market, 40% to "specialized, sophisticated, distinctive, and innovative enterprises", 50% to private enterprises, and 60% to emerging industries, showcasing its notable small-cap innovation characteristics. With the upgrade and the new launch, the SSE has established a flagship broad-based index system consisting of the SSE 50, SSE 180, SSE 380, and SSE 580 indices, reflecting the ultra-large, large, mid, and small-cap segments of the SSE. They include a total of 1,140 securities, covering about 50% of the number of securities and nearly 90% of the market capitalization on the SSE.

In line with the characteristics of "blue-chip, hard technology, and high dividends", the SSE index system has established a "one body, two wings" framework consisting of its Flagship Broad-based Indices alongside the STAR Market and Dividend index offerings. This system serves as a convenient channel to attract medium to long-term capital into the market and is an important part of the "long-term funds for long-term investment" ecosystem. The Flagship Broad-based Series includes the SSE 50, SSE 180, SSE 380, and SSE 580 indices, which comprehensively represent large, mid, and small-cap listed companies in the SSE, providing investors with essential tools for A-share investment allocation. The STAR Market Series reflects the characteristics of the SSE STAR Market, focusing on hard technology companies with high growth potential and innovative attributes. This series, represented by STAR Market Composite Index and the STAR 50 Index, offers greater flexibility than the flagship broad-based indices and allows investors to share the outcomes of China's technological advancements. The Dividend Series represents the performance of high-dividend stocks on the SSE. Notable for their high dividend yields and low volatility, these indices are suitable for ordinary investors looking for wealth management tools as they seek to buy and hold for long-term stable returns. The representative index for this series is the SSE Dividend Index.

Going forward, the SSE and CSI will continue to promote comprehensive reforms in the capital market, improve and enrich the SSE index system, and provide the market with more diversified investment targets and reference tools. As a result, we will encourage various types of long-term funds to make index-based investing, and accelerate the development of an index-based investing ecosystem focused on rational, value-based, and long-term investment.