On September 14, news emerged that following a rise in the U.S. core CPI in August, expectations for a Federal Reserve rate hike in September have surged, making an increase this week a high-probability event. LPL Financial's analysis of six tightening cycles since 1994 shows that the S&P 500 has averaged negative returns in the first four months after the initial rate hike, with an average increase of 6.7% over 12 months and a median of 10.7%. Notably, after the rate hike in March 1997, the S&P 500 rose by 42% over the year, while after the March 2022 hike, the maximum drawdown was approximately 25%. LPL believes the current macroeconomic environment is more akin to the late 1990s: the economy remains resilient, inflation is below the peak levels of 2022, and the starting interest rates are already relatively high. The AI investment boom may support capital expenditures. However, the firm does not expect a simple replication of the 42% increase seen in 1997, and the scale of this tightening cycle is unlikely to approach the cumulative 5.25 percentage points seen from 2022 to 2023.