Different from existing literature that primarily focuses on the direct impact of government-guided funds (GGFs) on invested enterprises, this paper innovatively examines how such funds influence innovation interactions among multiple invested enterprises. A limited body of literature has found that GGFs can significantly enhance corporate innovation performance. However, these investigations have largely concentrated on direct effects (such as capital provision and legitimacy empowerment), with limited in-depth analysis of positive externalities, particularly regarding innovation spillovers and industrial ecosystem development. Drawing on ecosystem theory, this study posits that GGFs can serve as ecosystem architects, constructing an innovation ecosystem centered on the GGFs through common shareholder connections, encompassing fund managers, co-investors, and numerous portfolio companies. Within this system, GGFs perform core organizational and coordination functions, enhancing entrepreneurial firms' embeddedness in the ecosystem by coordinating innovation interactions among ecosystem members. Specifically, GGFs promote innovation spillovers among portfolio companies through three mechanisms: information transmission, resource integration, and relational governance.

This study employs GGFs investment event data from 2003-2019, patent application data and patent citation data from 2000-2022, and utilizes parametric and non-parametric event study methods to systematically examine the effects and mechanisms of GGFs on intra-portfolio innovation spillovers. Empirical results demonstrate that after firms join GGFs portfolios, their innovation interactions with other portfolio companies are significantly enhanced. Mechanism tests reveal that GGFs facilitate inter-firm innovation collaboration through information transmission, resource integration, and relational governance channels, with these promotional effects being more pronounced when portfolio companies exhibit higher geographical dispersion, GGFs operate at higher administrative levels, and trust levels between entrepreneurial firms and portfolio companies are lower. Heterogeneity analysis results indicate that intra-portfolio innovation interactions are significantly enhanced when funds possess extensive investment experience, participate as lead investors, and have managers with state-owned backgrounds, or when entrepreneurial firms are high-tech enterprises, are in non-early development stages, represent cross-regional investment projects, and operate in regions with well-developed intellectual property protection systems. Further research reveals that intra-portfolio innovation spillovers effectively promote corporate innovation output, particularly demonstrating superior performance in core technology breakthroughs. These findings suggest that policymakers should deepen their understanding of the ecosystem-enabling functions of GGFs and refine institutional designs to fully unleash their positive externalities; fund managers should focus on optimizing operational mechanisms and strengthening innovation leadership and resource allocation capabilities; and enterprises should proactively integrate into innovation ecosystems and improve their innovation interaction strategies with portfolio companies.

The theoretical contributions of this study manifest in three dimensions: First, from an innovation ecosystem perspective, it deepens theoretical understanding of the mechanisms through which GGFs influence corporate innovation performance, extending the research perspective from individual firms to the portfolio level and providing ecosystem-level empirical evidence for how GGFs promote corporate innovation activities. Second, it reveals the unique functions of GGFs—as special common shareholders with public policy orientation—in shaping internal ecosystem structures and driving innovation spillovers, elucidating how equity-based coordination mechanisms uniquely facilitate innovation interactions within ecosystems and ultimately advance key core technologies. Third, by thoroughly examining the moderating effects of fund characteristics, firm attributes, and regional governance environments on the heterogeneous effects of intra-portfolio knowledge flows, it provides important insights for optimizing GGFs operational models and advancing innovation ecosystem evolution.