This time, the PCE data came in below expectations—not because the data improved, but because the calculation method changed. Back in early July, we talked about how the U.S. Bureau of Economic Analysis (BEA) would adjust the PCE price index calculation method on September 30, with historical data revisions going back to 2021. This adjustment mainly involves three categories: computer software, legal services, and portfolio management (investment advisory services). At the time, the market expected these adjustments to lower the year-over-year growth rate of core PCE by about 0.1–0.2 percentage points (for example, Goldman Sachs estimated that by May 2026, core PCE might be revised down from 3.4% to 3.2%).