Complete Guide to China's Six Core A-Share Indexes: Everything You Need to Know

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To understand the Chinese stock market, the first step is to watch A-share indexes. They are just like Taiwan’s Weighted Index and serve as the key indicator of overall market performance.

This massive market consists of two major exchanges—Shanghai and Shenzhen—with a considerable number of listed companies:

• Shanghai Stock Exchange: 2,263 listed companies as of the end of 2023.
• Shenzhen Stock Exchange: 2,844 listed companies as of the end of 2023.

To help investors quickly grasp the essentials, the table below summarizes the six most representative core indexes and their market positioning.

Key Points

• The A-share market consists of the Shanghai and Shenzhen exchanges with a huge number of listed companies.
• The six core indexes reflect different market styles and help investors understand the market.
• The SSE Composite and SZSE Component are foundational indexes that reflect overall market conditions.
• The CSI 300 Index is the A-share market barometer and represents mainstream stock performance.
• The ChiNext and STAR 50 indexes both represent technological innovation but focus on different areas.

Market Baseline Thermometer: SSE Composite and SZSE Component Index

Among numerous indexes, the SSE Composite Index and SZSE Component Index are the two most basic broad-market indexes. They respectively represent the overall status of the Shanghai and Shenzhen exchanges, acting like the temperature in a weather forecast and providing investors with the most direct sense of market warmth or coldness.

SSE Composite Index (Shanghai Composite)

The SSE Composite Index, commonly known as the “Shanghai Composite,” is the oldest stock index in China. It includes all stocks listed and traded on the Shanghai Stock Exchange, making it a broad indicator for observing overall market performance.

How is the Shanghai Composite calculated? It uses market-cap weighting, meaning the larger the company’s market cap, the greater its influence on the index. The calculation basis is as follows:

1. Base Date & Value: Base date is December 19, 1990, with a base value of 100 points.
2. Constituents: All stocks listed on the Shanghai Stock Exchange.
3. Formula: Current Index = (Current Total Market Cap / Base Period Total Market Cap) × 100.

Because its constituents include a large number of major state-owned enterprises, the Shanghai Composite’s trend is often used to reflect the macroeconomic situation of mainland China. As of May 2025, its total market capitalization reached RMB 64.05 trillion. However, its performance has also shown considerable volatility.

SZSE Component Index (Shenzhen Component)

The SZSE Component Index, referred to as the “Shenzhen Component,” selects the 500 companies with the largest market capitalization and best liquidity from those listed on the Shenzhen Stock Exchange as its constituents.

Unlike the Shanghai Composite, the Shenzhen Component’s constituents are more concentrated in private enterprises, SMEs, and sectors such as technology and manufacturing. Therefore, it is often regarded as an important window for observing China’s emerging industries and market vitality.

Differences Between the Two Broad Indexes

Simply put, the Shanghai Composite and Shenzhen Component are like two mirrors that respectively reflect different facets of the Chinese stock market. The table below clearly shows their core differences:

Understanding the differences between these two foundational A-share indexes is the first step to mastering the Chinese stock market. They provide investors with a basic perspective for observing the overall market picture and structural characteristics.

Core A-Share Indexes: Precise Depiction of Market Styles

The SSE Composite and SZSE Component offer a foundational view of overall market temperature. They tell investors whether the entire market is in the enthusiasm of a bull market or the cold winter of a bear market. However, merely understanding the overall temperature of the market may not be sufficient for formulating precise investment strategies.

This is like a city’s general weather overview that only tells us whether today is sunny or rainy. For hikers who want to know mountain weather or surfers who want coastal conditions, such information is clearly not precise enough. They need detailed data on wind speed, humidity, and specific temperatures.

For this reason, the market has developed more representative core indexes. These indexes are like more refined meteorological instruments that specifically measure the performance of particular stock styles, such as large blue-chip stocks, mid-cap growth stocks, or high-tech innovative companies. These core A-share indexes allow investors to more clearly identify the direction of market rotation and find the corresponding observation indicators based on their own investment goals.

In simple terms, if broad indexes answer the question “How is the overall market rising or falling?”, then core indexes further answer “Who is leading the market rise or fall?”

Understanding the positioning and differences of these core indexes is the key step from observing the market’s “broad trend” to analyzing its “structure.” Next, we will introduce these truly style-defining and highly valuable core indexes one by one, starting with the most representative “CSI 300 Index.”

CSI 300 Index: The Barometer of the A-Share Market

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If the SSE Composite and SZSE Component are the market’s “thermometer,” then the CSI 300 Index is the true “barometer” of the entire A-share market. It not only measures temperature but also reflects core trends and market health, making it one of the most closely watched indicators by institutional investors and overseas capital.

Index Definition and Positioning

The CSI 300 Index (CSI 300) consists of the 300 largest and most liquid stocks from both the Shanghai and Shenzhen exchanges. The design goal of this index is to reflect the overall performance of mainstream A-share stocks.

Because its constituents span both markets and are selected from the most representative leading companies, the CSI 300 Index is widely recognized as the most important and authoritative indicator for measuring the overall trend of the Chinese stock market. Its status and representativeness are comparable to the U.S. stock market’s S&P 500 Index.

Therefore, when analysts or media discuss “broad market” trends, they mostly refer to the CSI 300 Index rather than a single exchange’s composite index.

Constituents and Sector Distribution

The CSI 300 Index’s constituents include leading companies from every sector in China. For example, it includes new energy giant “CATL” as well as financial heavyweight “China Merchants Bank.” This broad coverage makes it an excellent window for observing the structure of China’s real economy.

From a sector distribution perspective, the CSI 300 Index exhibits a fairly balanced structure, avoiding the risk of over-concentration in a single sector. Its major sector weights are as follows:

This comprehensive coverage across finance, industrials, consumer staples, technology, and other sectors ensures the index’s stability and representativeness. When one sector is in a cyclical downturn, other sectors can provide balance. This is precisely why the CSI 300 Index can accurately reflect overall market conditions and is hailed as the “barometer.”

SSE 50 Index: Core of Mega-Cap Blue Chips

If the CSI 300 Index is the A-share market’s “All-Star team,” then the SSE 50 Index is the “starting lineup” of that team. It further focuses on the most elite and influential companies in the market.

Index Definition and Positioning

The SSE 50 Index (SSE 50) selects the 50 largest and most liquid companies from the Shanghai Stock Exchange. Its positioning is very clear: to represent the overall performance of Shanghai’s mega-cap blue-chip stocks.

These companies are typically leaders in their respective industries with stable profitability and market dominance. Therefore, the SSE 50 Index’s trend is often regarded as a key directional indicator for large high-quality stocks and core market assets.

Compared to the broader coverage of the CSI 300, the SSE 50 is more concentrated. Investors can use this index to precisely track the dynamics of the market’s most heavyweight companies.

Constituents and Sector Distribution

The SSE 50 Index’s constituents are all household-name giant enterprises that form the backbone of China’s economy. Due to its selection criteria, sector distribution is highly concentrated in traditional mature industries.

Its major sector weights are as follows:

• Financials & Real Estate: Occupies nearly half of the index—the absolute core.
• Consumer Staples: Covers food & beverage leaders essential to daily life.
• Industrials: Includes large infrastructure and manufacturing giants.

This structure gives it a distinct “value style.” Unlike indexes that emphasize technology growth, the SSE 50’s constituents are more like the economy’s stable “ballast stones.” Understanding this helps investors find the most suitable reference indicator when analyzing different market styles.

CSI 500 Index: Representative of Mid-Cap Value & Growth

After examining the mega-cap leaders represented by the SSE 50 and CSI 300, attention turns to mid-cap companies with greater growth potential. The CSI 500 Index (CSI 500) was created precisely to capture the performance of this group.

Index Definition and Positioning

The CSI 500 Index’s stock selection logic is very clever. It first excludes the top 300 companies by market cap in the A-share market (i.e., CSI 300 constituents), then selects the next 500 largest companies by total market cap from the remaining stocks.

This design makes the CSI 500 Index precisely represent the “mid-cap” power in China’s stock market. In the index’s selection universe, “mid-cap stocks” refer to the companies that, together with small-caps, constitute the index. These companies are listed on both Shanghai and Shenzhen exchanges and are important cornerstones of market depth and breadth.

Compared to large blue-chip stocks, these mid-cap companies are usually in faster growth stages with higher flexibility and vitality, making the CSI 500 Index a key indicator for observing market growth momentum and economic structural transformation.

Constituents and Sector Distribution

The CSI 500 Index’s sector structure differs significantly from large-cap indexes—it substantially reduces financial weighting and instead focuses more on areas representing new economic forces. Its major sector distribution covers:

• Industrials
• Information Technology
• Communication Services
• Pharmaceuticals
• Healthcare

The index constituents include many “hidden champions” with core technologies in niche fields. For example, Dinglong Co., Ltd., which specializes in innovative semiconductor materials; KBC Corporation, a leader in carbon-based composite materials; and Sunresin, which has achieved technological breakthroughs in adsorption and separation materials. These companies fully demonstrate the strong growth potential of China’s A-share mid- and small-cap companies. This blend of value and growth characteristics makes the CSI 500 Index an important reference for investors to discover future market stars.

ChiNext Index: Cradle of High-Growth Innovative Companies

If the CSI 500 Index represents the market’s backbone, then the ChiNext Index represents the market’s future imagination. It focuses on high-growth innovative companies and is often compared to “China’s Nasdaq.”

Index Definition and Positioning

The ChiNext Index selects the 100 largest and most liquid companies from Shenzhen Stock Exchange’s ChiNext board. The ChiNext board itself was established to provide financing channels for innovative companies in early-to-mid growth stages.

Therefore, the ChiNext Index has a very clear positioning: it is an indicator specifically designed to measure the performance of high-tech, emerging, and strategic emerging industry companies—the core window for observing the vitality of China’s innovation-driven economy.

Its movements reflect the market’s risk appetite and expectations for technology and innovation, with volatility typically higher than main-board indexes.

Constituents and Sector Distribution

The ChiNext Index constituents include many leading companies in emerging fields, such as the world’s largest power battery manufacturer “CATL,” the internet financial service platform “East Money,” and solar inverter leader “Sungrow Power.” These companies represent the new drivers of China’s economic transformation.

The table below lists the top 10 heavyweight stocks of the ChiNext Index, showing its highly concentrated nature:

From a sector perspective, the ChiNext Index clearly leans toward emerging industries. Its major sector distribution is concentrated in:

• Industrials: 37.07% (including many power equipment and new energy companies)
• Healthcare: 24.77% (mainly biopharmaceuticals)
• Information Technology: 19.83% (covering electronics, computers, etc.)

This tech- and healthcare-centric structure sharply contrasts with broad indexes that emphasize finance and consumer sectors, and also gives it higher comparability with the U.S. Nasdaq Index.

STAR 50 Index: Pioneer of Hard-Tech Innovation

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If the ChiNext board is the cradle of emerging industries, then the STAR 50 Index is more like a “special forces unit” focused on breakthrough core technologies. It represents the most cutting-edge and core segment of China’s technology innovation spectrum.

Index Definition and Positioning

The STAR 50 Index selects the 50 largest and most liquid stocks from the Shanghai Stock Exchange’s STAR Market. The STAR Market itself was established to serve technology innovation companies that align with national strategy and possess key core technologies.

Therefore, the STAR 50 Index has an extremely precise positioning: it is an authoritative indicator specifically measuring the overall performance of China’s “hard-tech” companies. “Hard tech” here generally refers to fields that require long-term R&D investment, have high technical barriers, and are difficult to imitate or replicate.

Compared to ChiNext’s broad coverage of emerging industries, the STAR 50 Index focuses more intensely on frontier fields that will shape future technology—such as semiconductors, artificial intelligence, and biotechnology. Its trend directly reflects market confidence and expectations regarding China’s core technology self-reliance.

Constituents and Sector Distribution

The STAR 50 Index constituents are pioneers in China’s hard-tech fields, such as foundry leader “SMIC” and office software giant “Kingsoft Office.” These companies generally feature high R&D investment and strong technical moats.

From a sector perspective, the STAR 50 Index’s industry distribution is highly concentrated and distinctly different from other A-share indexes. Its major sectors are concentrated in:

• Next-Generation Information Technology: Accounts for nearly half the index weight, centered on the semiconductor industry.
• Biopharmaceuticals: Covers innovative biologics and medical device companies.
• High-End Equipment Manufacturing: Focuses on smart manufacturing, aerospace, and other fields.

This highly focused structure on technological frontiers makes the STAR 50 Index the purest indicator for observing China’s technological strength and innovation momentum. It represents high growth potential while also coming with higher market volatility, clearly delineating both the risks and opportunities in the hard-tech sector.

This article has fully introduced the six core A-share indexes that cover overall market performance, large-cap blue chips, mid-cap growth, and technological innovation. Understanding the differences among these A-share indexes helps investors more accurately judge market style and trends.

To help you quickly review, the table below clearly positions each A-share index’s market role from the two dimensions of “market cap size” and “style attribute”:

FAQ

There are so many A-share indexes—how should investors choose?

Each index has its unique market positioning. Investors should first understand their own goals and then select the corresponding observation indicator.

• Track large-cap blue chips: Focus on CSI 300 and SSE 50.
• Seek mid-cap growth: Refer to CSI 500.
• Focus on tech innovation: Study ChiNext and STAR 50.

What is the difference between CSI 300 and SSE 50?

The main differences lie in coverage and number of constituents. SSE 50 only includes the 50 largest companies from the Shanghai market—more concentrated. CSI 300 spans both Shanghai and Shenzhen markets and selects the 300 most representative companies—broader coverage.

Both ChiNext and STAR represent tech stocks—what’s the difference?

They represent different levels of technological innovation. The ChiNext Index has a broader scope, while the STAR 50 Index focuses more strictly on high-barrier “hard-tech” fields.