In an era of rapid global finance, sudden shifts in capital flows challenge emerging and advanced economies alike. Policymakers deploy an array of tools to stabilize exchange rates, cushion liquidity shocks, and sustain growth during episodes of sudden stops or reversals. Yet the effectiveness of these instruments hinges on credible design, timely deployment, and coordination across domestic institutions and global partners. This evergreen piece examines why capital flow volatility arises, how policymakers can diagnose vulnerabilities, and which policy mixes have proven resilient in protecting outputs without causing unintended distortions. It offers actionable insights for policymakers, researchers, and observers seeking durable macroeconomic stability.