Alphacast High Frequency CPI: Inflation was 2.5% MoM in December

December inflation barely eased. Headline prices rose 2.5% MoM, down from 2.6% MoM in November, while the annual rate ticked up to 30.2% YoY.

Throughout the reference month, core and seasonal prices decelerated, while regulated prices accelerated. Core inflation came in at 2.39% MoM, well below the prior month’s revised 2.72% MoM. Seasonal items rose 1.69% MoM, down from November’s revised 1.76%, while regulated prices increased 3.13% MoM, up from November’s revised 2.7%. Core items accounted for 1.36 percentage points of headline inflation, regulated items contributed 0.90 pp, and seasonal components added 0.23 pp. Excluding regulated prices, monthly inflation would have been closer to 1.6%.

The carryover from November into December rose to 0.9%, below last month’s figure. Meanwhile, end-of-period inflation over the last four weeks reached 2.2%.

Inflation picked up on a weekly basis in the last week of December and early January (December 29–January 4). Consumer prices rose 0.43% WoW, up from the previous week’s revised 0.29%. On a monthly basis, the pace decelerated sharply to 2.2% MoM. Meanwhile, the annual rate came in at 29.8% YoY, broadly in line with the prior week’s revised 29.9%.

Core, seasonal, and regulated prices accelerated slightly. Core prices rose 0.50% WoW, above the previous week’s revised 0.30%. On a monthly basis, core inflation was 2.1% MoM, below the prior week’s run rate. Seasonal items climbed 0.38% WoW (vs. a revised 0.29% previously), while their monthly pace eased to 1.5% MoM. Regulated prices increased 0.28% WoW, and their monthly pace slowed to 2.8% MoM.

Market forecasts remained cautious, with optimism fading over the month. Reflecting an apparent inertial floor, inflation expectations for December were revised up to 2.09% MoM. The 2025 outlook was revised up to 30.4%, 0.8 pp above the previous REM estimate of 29.6%. Projections for 2026 increased to 19.62%, while the 2027 forecast points to inflation of around 11.5%, also above the November estimates.

Note: Starting from the week of June 9th, weekly variation dates correspond to the first day of each week. For example, the week of June 23rd covers the period from June 23rd to June 29th. Prior to this change, weeks were counted from Wednesday to Tuesday; now, they run from Monday to Sunday.