["Psychology &Marketing, Volume 43, Issue 6, Page 1432-1444, June 2026. ", "\nABSTRACT\nAs athletes increasingly shift from traditional endorsements to entrepreneurial ventures such as co‐investment and self‐branding, the question of how these strategies affect consumer trust remains underexplored. Drawing on signaling theory, this study examines how athlete‐brand relationships of varying costliness serve as signals of athlete involvement, a key unobservable attribute that drives trust. Across two experiments conducted in the U.S. and China, results show that high‐cost signals (co‐investment and self‐branding) are significantly more effective in enhancing perceived involvement and trust than low‐cost signals (endorsements), particularly among skeptical consumers. This study provides empirical support for the logic of separating equilibrium and explains when and why entrepreneurial athlete branding strategies enhance trust, offering practical implications for athlete branding, influencer marketing, and digital entrepreneurship in social media environments.\n"]