The stock exchange market is a crucial component of the economy, providing investors with the opportunity to participate in the shares of different enterprises. This study investigates the influence of the United States Dollar exchange rate and foreign direct investment (FDI) on the Karachi Stock Exchange-100 index, a key component of the Pakistan Stock Exchange. Utilizing monthly data from July 2008 to March 2023, the research employs an Augmented Dickey-Fuller test for stationarity and Johnson Cointegration test for model confirmation. Results from the Granger Causality test highlight significant long-term relationships between FDI, inflation, interest rates, balance of payments, and the Karachi Stock Exchange-100 index. Conversely, the exchange rate and FDI exhibit statistical insignificance in the short term. Introducing moderation effects, the exchange rate demonstrates negligible long-term impact but reveals a negative short-term association with the Karachi Stock Exchange-100 index. Impulse response analysis indicates positive reactions to shocks for FDI, balance of payments, and the dollar exchange rate, with inflation and interest rates exhibiting negative responses. The study's novel contribution lies in uncovering the nuanced temporal dynamics between economic indicators and the stock market, offering valuable insights for policymakers crafting investment strategies to navigate market volatility and enhance stock market returns.