#每周来晒 #8月CPI数据出炉

US August CPI: Why Did Markets Rally Despite Hotter-Than-Expected Inflation?

The US August CPI report released on the evening of September 11 painted a hawkish picture at first glance. While the headline numbers came in line with expectations, a 0.1 percentage point deviation in the details completely repriced the Fed outlook. The paradox followed immediately: even as rate-hike expectations surged, equity futures, gold, and silver all moved higher together. To understand the rally on bad news, you have to read the second layer of logic.

1. Where Exactly Was the Beat?

On a year-over-year basis, the picture looked calm. Headline CPI rose 3.4% YoY, exactly matching consensus. Core CPI, excluding food and energy, slowed from 2.5% in July to 2.4% YoY, also meeting expectations and marking the lowest annual core reading since March 2021.

The problem was in the monthly momentum. Core CPI rose 0.3% month-over-month. The market was expecting 0.2%, so the print came in hotter than forecast and matched the July increase.

Why does 0.1% matter so much?

Because institutions had built a clear threshold framework for the Fed in recent weeks: 0.1% or less on monthly core - the Fed stays on hold, 0.2% - uncertainty persists, 0.3% or higher - a September hike becomes the base case. The reported 0.3% landed right on that trigger line, bolstering the case for a hike.

The breakdown makes the source of pressure clearer. Shelter rose 0.3% MoM, communications jumped 2.3%, and airfares surged 2.7%. In other words, inflation is no longer being driven by goods, but by sticky services. On the annual side, the energy pass-through is striking: the gasoline index is up 27.4% YoY and the energy index 16.3%, as the earlier break above 100 dollars per barrel in oil prices begins to feed into transportation and services.

When the two components the Fed watches most closely - housing and energy - rise together, that 0.1-point miss was enough to push the probability of a September hike from 71% to 90%.

2. Why Did the Market Rally Instead of Selling Off?

This is where the second layer kicks in.

After the release, the market's question was no longer "Will there be a hike in September?" but "How many more hikes will there be?" Under normal conditions, that should be an outright negative for risk assets. Yet US stock futures turned higher following the slightly stronger-than-expected core reading, gold rebounded quickly to around 4,344 dollars after dipping below 4,300 dollars, and the 30-year Treasury yield, after briefly surging to 5.36% - its highest since 2007 - started to give back its gains.

There is only one explanation: the bad news was already priced in.

The market had sold off for three to four consecutive days in the week leading up to the data. The Philadelphia Semiconductor Index had plunged 2.66% before the release, and the bond market had already front-run the hawkish scenario. When everyone knows the shoe is about to drop, the moment it actually drops is less frightening.

What we saw was a classic sell the rumor, buy the fact formation. Those who needed to sell had already sold, those who needed to de-risk had already de-risked. The remaining liquidity started to reassess: How much worse can a 90% hike probability get?

The market is not saying rate hikes are good. The market is saying: I already knew this, so I can turn the page and focus on the terminal rate.

While near-term volatility will persist, this price action tells us something important: as inflation's capacity to surprise diminishes, the market's focus is shifting from what the Fed will do to when it will stop. And the slightest hint about that stopping point can become a more powerful catalyst than even the most hawkish data point itself.