This study explores the convergence between the prices of American Depositary Receipts (ADRs) listed by Asia–Pacific firms and their original shares listed on home exchanges. Instead of relying on conventional parametric approaches that carry embedded model-specification errors, we contribute to the literature by introducing a nonparametric technique to estimate the convergence speed parameter. We present the time-varying characteristics of both firm and country-level convergence speed parameters. Furthermore, we empirically verify and visually corroborate the comparative dynamics of convergence with respect to short sales restrictions, trading time differences, and market-tier measures proxied by the Morgan Stanley Capital International indices. We conclude that enhancement in market efficiency accelerates the reversion to the parity of ADR-pairs.