The US December Unadjusted Core Consumer Price Index (CPI) rose 2.6% year-over-year, slightly below the expected 2.7% and matching the previous month's figure. This unexpected result has led to a significant rally in US short-term interest rate futures, as traders anticipate potential rate cuts by the Federal Reserve. Meanwhile, the overall CPI remained steady at 2.7%, aligning with market expectations and the previous month's data.