Abstract: The illegal activities of the bond-issuing enterprises hidden behind bond defaults have severely disrupted the order of the bond market. So, as an innovative investor protection system for regulatory minority shareholders to carry out right exercise activities, can China Securities Investor Services Center (CSISC) produce a spillover effect on the bond market? Based on this, taking the bonds publicly issued by Shanghai and Shenzhen A-share listed companies from 2016 to 2023 as samples, this paper empirically examines the impact of CSISC's exercise of rights on the credit spread of bonds. The research reveals that CSISC's exercise of rights has significantly increased the credit spread of bonds. The mechanism analysis shows that CSISC's exercise of rights can exert a signal effect, transmitting the signal of poor governance and capital situation of the listed companies to bond investors, thereby increasing the credit spread of bonds. The heterogeneity test reveals that when the regional credit environment is weak, the degree of protection for enterprise investors is relatively lower, and the investor learning effect is insufficient, CSISC's exercise of rights has a more prominent effect on enhancing the credit spread of bonds. In addition, CSISC's exercise of rights has increased the issuance cost of bonds in the primary market and exacerbated the risks of financial distress it faces after raising the credit spread of bonds in the secondary market. Therefore, the listed companies need to continuously improve their information disclosure and enhance their bargaining power in the bond market. The regulatory authorities should use the right exercise activities of investment service centers to prevent and resolve systemic financial risks, thereby promoting high-quality development of the capital market.

Key words: exercise of rights by CSISC, bond credit spread, investor protection, spillover effect