The March inflation report had two very different stories inside it.
Pull out gas, and the picture looks calm. Leave it in, and prices just had their biggest monthly jump in a long stretch.
The Iran conflict is why those two stories don't match.
CPI - or the Consumer Price Index, the main gauge of what Americans pay for everyday stuff - rose 0.9% in March. That's after a 0.3% bump in February.
Over the past year, prices are up 3.3%.
Energy did most of the damage. Energy prices climbed 10.9% in March. Gas alone jumped 21.2%. The government said gas accounted for roughly three quarters of the whole monthly jump.
Core CPI - the version that leaves out food and gas to show the underlying trend - rose just 0.2% on the month and 2.6% over the year. Both came in a tick below what economists expected.
Shelter, which is the biggest single line item in the index, rose 0.3%. Food was flat. Restaurants up 0.2%. Groceries down 0.2%.
Translation for investors: outside the pump, prices behaved.
The gap between the 3.3% headline and the 2.6% core is basically the Iran premium. When oil jumps because of a conflict, gas goes with it. Gas then drags the whole headline number up for the month.
A one-month oil spike isn't normally something the Fed - the central bank that sets interest rates - fights. They treat those as temporary. Here today, gone next quarter.
The problem is what it does to expectations. One tracker flagged two-year inflation expectations as high, and that's the metric the Fed watches closely.
Think of it like a thermostat with memory. One hot day won't move it. A pattern of hot days does.
That's why the Fed has stayed cautious on rate cuts even as core inflation cools. Cutting too early and getting hit by a second oil shock would undo years of work.
Three things on the radar.
First, oil. If the Iran situation stays quiet, gas should come back down and the April headline number will look a lot friendlier.
Second, core. Another 0.2% month would tell the Fed the underlying trend is genuinely cooling, separate from the oil noise.
Third, rent and shelter. That one category is almost a third of CPI. It's been the stickiest piece of the puzzle for years.
March was loud because of gas. The core number was the quieter one - and it's the one the Fed was actually waiting on.
