September inflation sends Treasury yields surging

In September, US consumer prices surged due to increased fuel costs, impacting President Donald Trump and his Republican Party as the midterm elections approached later in November. The Consumer Price Index (CPI) climbed 0.6% in September, following a 0.4% increase in August, according to the Labor Department's Bureau of Labor Statistics.

Over the past year, the CPI grew by 3.7%, compared to a 3.4% rise in the previous year. Economists polled by Reuters had anticipated a 0.6% month-over-month rise and a 3.6% increase year-over-year. Petrol prices spiked by 7.1% in September, according to the US Energy Information Administration. The rise in prices coincided with a decline in consumer sentiment and a drop in Trump's approval ratings, mainly due to the cost-of-living concerns.

A Reuters/Ipsos poll indicated that 78% of Americans blamed Trump's policies for the rising prices, which surpassed wage growth. Excluding volatile food and energy components, the CPI still increased by 0.3% in September, matching the gain in August. The CPI is a key indicator for the US Federal Reserve, which aims to maintain a 2% inflation target.

The core CPI, which excludes food and energy components, has lagged behind the core PCE inflation, which rose by 3% in August. The Federal Reserve raised its benchmark interest rate by 25 basis points to the 3.75%-4% range in October, signaling potential further increases in borrowing costs. Prior to the CPI report, financial markets gave a roughly 22% chance of a rate hike at the October 27-28 policy meeting.

The September CPI report provided crucial information for millions of retirees and Social Security recipients, who rely on the CPI for determining the annual cost-of-living adjustments (COLA) for Social Security and Supplemental Security Income benefits in 2027. The Senior Citizens League forecasted a 3.5% COLA increase, raising the average monthly benefit for retirees to $2,007, up from $2,000 in 2026. The Social Security Administration will announce the COLA increase for 2027 on October 14.