Background/Objective: The Federal Reserve's 525-basis-point tightening cycle (2022-2023) created a high-velocity stress test for the U.S. banking system. This paper uses an event study approach to investigate the impact of 2022-2025 interest rate decisions on the stock prices of selected regional banks (RF, FITB, KEY, HBAN) compared to large-cap banks (JPM, BAC, WFC, C). Methods: Official Federal Open Market Committee (FOMC) announcement dates were utilized as events [1]. Abnormal returns (AR) and cumulative abnormal returns (CAR) were calculated against the S&P 500 using a market model (CAPM) and a constant-mean return model [2, 3]. The study employed a -120 to -6 day pre-event estimation period and a -5 to +5 day event window [4], with significance verified via t-tests [5]. Results: Banks showed positive ARs on event days due to improved net interest margins [6]. Regional banks demonstrated stronger effects than large-cap banks (+0.82% vs. +0.10% on the announcement day), supporting deposit-franchise theory: regional firms benefit more from rate increases due to higher costs for rate-sensitive liabilities [7]. Conversely, large banks exhibited smaller ARs, likely reflecting higher global funding costs [1]. By Q3 2025, regional bank valuations faced a "fragility discount" amid $337.1 billion in unrealized losses driven by persistent commercial real estate (CRE) concerns. Conclusions: Interest rate shocks transmit unevenly; while tightening generally depresses risk assets [8], banks can be an exception [6]. The 2025 easing cycle lacked perfect symmetry, as persistent CRE risks tempered valuation gains even as the Federal Reserve transitioned to rate cuts.