In contexts marked by information asymmetry, second-hand home buyers often rely on market signals to guide their trading decisions. This study, based on data from online judicial auction transactions across 14 Chinese cities, investigates the impact of information dissemination mechanisms on asset valuation accuracy. The study findings suggest that the information transmission framework of the judicial auction housing market is primarily composed of market demand signals and comprehensive online/offline information. The results indicate that stronger demand signals correspond to higher transaction prices for judicial auction properties, though this relationship exhibits a non-linear effect on valuation errors. Furthermore, enhanced clarity in the dissemination of both online and offline information is associated with diminished disparities in asset valuation, concurrently mitigating the skewing influence of market demand indicators on asset prices. Empirical evidence highlights the existence of irrational constituents within these signals, accentuating the imperative to refine the disclosure of online information and augment offline services, thereby improving the quality of asset valuation in the burgeoning market of online real estate transactions.