Inflation Slowed. That Wasn’t the Same as a Pleasant Surprise.

I can say October inflation slowed from September and also say the release was a disappointment relative to expectations. Those statements use different benchmarks. If I start with the market’s reaction and work backward, I am likely to confuse them. The monthly headline rate fell from 0.6% to 0.4%, while core held at 0.3%. That mix is more informative than describing the entire report as either hot or cool.

The missing October 2025 observation makes the usual annual comparison unavailable for most CPI series. I would not quietly substitute September’s annual figure, or take one monthly number and present its annualized equivalent as the actual change over a year. An annualized pace answers what would happen if a monthly rate persisted. The missing comparison asks what did happen. They are not the same question.

A higher discount rate can reduce what I am willing to pay for the same expected cash flows. A lower sales estimate changes the cash flows themselves. I would rather record those adjustments separately. AMD’s fourth-quarter sales outlook gives me a test for one company’s revenue; it tells me little about where inflation will settle. Conversely, a disappointing CPI print does not tell me how many chips AMD shipped. Keeping those questions apart makes it easier to revisit a valuation when the next actual result arrives.