This paper examines the impact of currency volatilities on the average monthly spreads in ADRs and their underlying local shares. We employ a novel estimator for spreads based on two-day-period high and low values of a comprehensive universe of stocks over fifteen years using dynamic panel data estimation. Surprisingly, we find that currency volatility has a larger impact on spreads of ADRs than on their underlying local shares. This adds novel information to the well-documented evidence that local shares and exchange rate variations are the primary drivers of ADR returns. FX implied volatility accounts for about 16.6% of the variance in our sample. We also observe that, on average, ADR spreads are smaller than the spreads on their corresponding underlying shares. We posit that size matters and therefore provide measures of the economic significance of all our estimated results.