Waller puts a half-point Fed hike on the table, and today's inflation report could decide it

"Let's just say it. September's inflation data were bad." Christopher Waller, a Federal Reserve governor, said so in London on Tuesday morning, a few hours before the October consumer price report. Then he named a number. If core CPI comes in "around 0.3 percent or even higher", he said, "a 50 basis point hike in the policy rate should be considered at the December meeting."

The threshold matters more than the adjective. The Bureau of Labor Statistics reported that core prices, which exclude food and energy, rose 0.3% in September. Waller is not asking for a new surge in inflation. He is asking whether the recent pace continues.

A base case that is already hawkish

Waller's starting point is a hike either way. "I would still support a 25 basis point increase in the FOMC's policy rate at our December meeting," he said, even if October's data improve on September's. The Fed held its target range at 3.75% to 4% on 28 October, in a 10-2 vote. The two dissenters, Lisa Cook and Beth Hammack, wanted a quarter-point rise then.

That makes Waller's message one of escalation, not conversion. He backed holding in October, and now argues that only a half-point would protect the Fed's standing if inflation stays hot. "Hiking only 25 basis points would put our credibility at risk," he said, "a risk I am not eager to take." He also warned that "energy price pressures may pass through to goods and services in a more sustained way than in the past".

His own numbers show why. Headline PCE inflation, the Fed's preferred gauge, rose 0.5% in September and 3.7% over the year, he said, and core PCE was up 3.1%. More than 70% of core PCE services components were rising faster than 3% a year.

What traders are pricing

Polymarket traders put the chance of a quarter-point rise at the December meeting, which ends on 9 December, at 86.5% (as of 10 November), up 14 points in a week. They give 7.5% to no change, down 15 points in a day, and 0.5% to a cut. A rise of half a point or more stood at 4.5%, up almost 3 points in a week.

A separate market on whether the Fed raises rates again at any point in 2026 reads 91%, up 18.5 points in a week. Add the December quarter-point and half-point outcomes together and you get 91%, so almost all of the expected tightening is concentrated in one meeting rather than spread across the winter.

The gap in the data is the half-point. Waller has told markets which print would justify it, and that print is the same as the last one. Yet traders give it about a one-in-twenty chance at most. Either they expect core inflation to ease below 0.3%, or they doubt the committee would follow one governor's lead.

The inflation market tells a similar story. Traders put 94% on October's annual rate matching September's 3.7%, although that market is small, with only about $39,000 traded. The annual rate would then stay flat, even as the monthly core figure decides the argument.

The case for stopping at a quarter-point

There are good reasons the market may be right. Waller is one of 12 voters, and the committee's October statement said only that it would "gather more information" on the right stance. Core CPI rounds, and a reading of 0.28% and one of 0.34% are both "around 0.3". The word he used was "considered", not "will".

Energy is the other uncertainty. Waller's concern is that the oil shock will spread to wider prices, but a softer headline figure from cheaper fuel would say little about services inflation. A cooler core number would let him argue the pass-through is slower than he feared.

The risk in the other direction is that a hot core reading arrives after Waller has publicly set the bar. A reading of 0.4% or more would make a half-point hard to dismiss, and the 4.5% price would have to move a long way.

Waller has made the data the decision. The print will tell us who was listening.