海外经验和国内溢价：ETF扩容能稳定提升信用债流动性吗

1. Report Industry Investment Rating No relevant content provided. 2. Core Viewpoints of the Report - The increase in the scale of the US ETF market has a temporary impact on the turnover rate, and the liquidity premium of domestic bond ETF component bonds is already relatively high [1]. - The expansion of ETFs is difficult to bring about a continuous improvement in the liquidity of component bonds. The liquidity premium of some component bonds is already at a high level, and the valuation difference between the exchange and the inter - bank market may lead to a narrowing of the spread [2][5][6]. - It is recommended to pay attention to the impact of market sentiment changes on liquidity [6]. 3. Summary According to the Directory 3.1 US Bond ETF Market Scale and Liquidity Comparison - The scale of the US bond ETF market increased significantly from 2023 - 2024 and declined significantly in 2025. In 2023, the scale was $554.482 billion, rising to $1152.808 billion in 2024 with a growth rate of 107.9%. As of June 2025, it was only $441.57 billion [2][11]. - During the periods when the scale of the US bond ETFs increased, the turnover rate of US credit bond ETFs increased significantly in 2022. However, in the long - term, there is no obvious positive correlation between the increase in the scale of US bond ETFs and the change in the turnover rate [2][12]. 3.2 Current Changes in Domestic ETF Liquidity and Component Bond Liquidity - Under the expansion of ETFs, the number of component bond transactions has increased significantly. Taking the Shanghai Stock Exchange AAA Benchmark Market - making Credit Bond Index as an example, the proportion of component bonds in the top three component entities has been continuously rising since 2025, reaching 91.7% since July [21]. - The valuation difference between the exchange and the inter - bank market for medium - long - term and medium - high implicit rating component bonds is more obvious. The spread between Shanghai market - making component bonds and inter - bank comparable bonds is currently between - 1BP and 13BP. The spread difference between central enterprises and local industrial state - owned enterprises is more obvious, while that of urban investment and transportation - related entities is relatively small [21]. - The exchange - inter - bank excess spread of science and technology innovation bond component bonds has widened since July [22]. 3.3 Component Bond Liquidity Pricing: Reasonable Liquidity Premium and Potential Risks - The reasonable pricing anchor for liquidity premium is within 10BP. Since 2024, under the expectation of debt resolution, the spread between high - grade urban investment bonds and secondary capital bonds is centered at 0, and the spread fluctuation range is basically within 10BP. The same is true for the spread between high - grade securities firm bonds and secondary capital bonds [35]. - The risk points of the valuation difference between the exchange and the inter - bank market: the spread of some benchmark market - making bonds and science and technology innovation bonds between the exchange and the inter - bank market has exceeded 10BP, and the spread of some component bonds with high institutional buying enthusiasm has exceeded 15BP [35]. - Three views on liquidity premium and risk points: ETF expansion is difficult to bring continuous improvement in component bond liquidity; the liquidity premium of some component bonds is already at a high level; after the valuation difference between the exchange and the inter - bank market, the exchange corporate bonds become more offensive, while inter - bank bonds are more defensive, and the spread may narrow with the increase in supply [36].