The Role of Key Factors in the Relationship Between Exchange Rate and Stock Market

This paper revisits the exchange rate–stock return nexus by examining how macro-financial fundamentals—specifically interest rate and inflation differentials relative to the United States—shape the impact of currency fluctuations on equity markets in 14 developed and 16 emerging economies. Motivated by gaps in the literature that overlook threshold behaviour, cross-sectional dependence, and distributional heterogeneity, the paper develops a novel two-stage CCE-augmented Panel Smooth Transition Regression (PSTR) model combined with Quantile Treatment Effects (QTE). This methodological innovation enables the identification of nonlinear regime shifts driven by macroeconomic differentials while addressing endogeneity and global spillovers. The results reveal sharp regime transitions associated with interest rate and inflation thresholds, particularly in developed markets. In emerging markets, exchange rate depreciation significantly lowers stock returns only when inflation differentials exceed a critical threshold, underscoring the role of macroeconomic instability. For developed markets, high-interest rate differentials magnify the negative effect of exchange rate fluctuations on equity performance, consistent with carry-trade dynamics. QTE analysis shows that emerging markets underperform during bearish conditions due to higher exchange rate volatility but outperform during bullish phases, reflecting a conditional “high-risk, high-return” pattern. These findings offer new insights for monetary authorities, investors, and portfolio risk managers.