CPI +0.4% (vs +0.4% Est) — Core Printed 0.3% Against 0.2%, and Core Was the Session

Fundamentals · 2026-09-11

CPI +0.4% m/m and +3.4% y/y, both exactly as forecast; but core rose 0.3% against 0.2% expected, its fastest month since April, while core y/y fell to 2.4% from 2.5% — also as forecast. Gasoline +3.9% was 36.8% of the entire headline on a 3.77% weight; energy +2.1% m/m and +16.3% y/y; fuel oil +10.1% m/m and +52.0% y/y. Shelter re-accelerated to +0.3% from 0.1 — but a third of that came from lodging away from home, which is 4% of shelter's weight and had fallen 2.8% the month before. Airline fares +2.7% seasonally adjusted and -0.5% unadjusted, +23.4% on the year. Medical care -0.2% and motor vehicle insurance -0.8% took roughly 0.035pp off core, which printed 0.3% anyway. Core's 3-month annualized rate is 2.0%; the single month annualizes to 3.7%.

What It Changes

• The one number that mattered came in hot. Three of the four figures on the calendar landed exactly on consensus. The fourth — core m/m — printed 0.3% against 0.2%, and that was the entire fulcrum of the session.
• It makes 16 September live in a way it was not yesterday. The market went into this at roughly 69% for a hike. Core at 0.3% with crude where it is removes the argument that the committee can wait one more month.
• But the annual core rate still fell, to 2.4% from 2.5%, and core's three-month annualized pace is 2.0% — slower than its own twelve-month rate. The hawkish case rests on one month, not on a trend.
• The August timing matters more than the number. This reading predates Brent above $100, the Saudi output loss and this week's escalation. Whatever energy did to this print, it does more to the next one.

Impact

• USD — Bullish — a hawkish core surprise five days before a live meeting, on the one decimal the market said it was trading.
• The asymmetry cuts against the size of the move, not its direction: DXY absorbed a hot PPI, an ECB hike and a $5 crude swing this week without moving, which is a currency that has already paid for the hike. Confirmation buys less than a surprise would.
• EUR is 57.6% of the DXY basket, so the index's response runs through the euro leg regardless of what the rest of the majors do. The ECB raised 25bp to 2.50% on Thursday and declined to call it a ceiling, which caps how far that leg can carry the dollar.
• US Indices (ES / NQ / YM / RTY) — Bearish — the read is strongest for RTY. Small caps led the overnight bid and carry the most rate sensitivity of the four.
• Equity went into this bouncing on an unconfirmed report of an Oman meeting. A hot core is the confirmation that a market rallying on diplomacy did not want.
• Gold (GC) — Bearish — gold has spent three sessions falling into rising yields, which is gold trading as a rates instrument rather than a haven. A hot core reinforces the rates leg.
• The divergence worth watching is the regime one: if gold starts rising alongside yields, the market has stopped believing the Fed can contain this. That is a change in kind, not a daily move.
• Crude (CL) — no directional read from this release — causation runs the other way here. Crude prices CPI, not the reverse.
• The forward point is mechanical: energy contributed 0.154pp of this 0.4% headline from a 7.3% weight, and this is an August basket. September's energy contribution is already larger before anything else happens.

Inside The Number

The Consumer Price Index rose 0.4% in August on a seasonally adjusted basis after 0.1% in July, and 3.4% over twelve months before seasonal adjustment — the same 3.4% as the twelve months ending July. Consensus was 0.4% and 3.4%. Both landed.

Core — all items less food and energy — rose 0.3% after 0.2% in July, against a 0.2% consensus. Its twelve-month rate fell to 2.4% from 2.5%, which was also what forecasters expected. So of the four numbers on this morning's calendar, three printed exactly as written and one did not, and the one that did not is the only one anybody was trading.

The headline itself is an energy story and BLS says so in its second paragraph: the gasoline index rose 3.9% and accounted for "over one third of the monthly all items increase." That checks out independently. Gasoline carries a 3.770% relative importance, so 3.9% on that weight contributes 0.147 percentage points of a 0.4-point headline — 36.8%. Energy as a whole rose 2.1% and contributed 0.154pp, or 38.6%, on a 7.347% weight. Food contributed 0.014pp. Core contributed 0.237pp. Those three sum to 0.405, which is the headline.

The energy year-over-year numbers are the ones to keep. The energy index is up 16.3% over twelve months, gasoline 27.4%, energy commodities 28.0%, and fuel oil 52.0% after rising 10.1% in August alone. Against that, electricity is up 3.8% and piped gas 4.4% — both of which actually fell on the month, electricity 0.2% and gas 1.1%. The inflation is in what gets burned in an engine, not what comes through a meter.

That is the direct sequel to yesterday. Producer prices put final demand energy at +24.4% over twelve months and diesel at +24.1% in the month of August. Consumer energy is up 16.3% over the same twelve months. The 8.1-point gap between what producers are paying and what consumers are paying is margin, and yesterday's producer report showed exactly where it is being absorbed: fuels and lubricants retailing margins fell 11.3% in the month their product rose 24.1%. Today's fuel oil line — up 10.1% in a month, 52.0% on the year — is the part that got through.

Now the part the headline hides, which is that core printed 0.3% despite two significant drags. The medical care index fell 0.2%, with dental services down 0.6% and hospital services, physicians' services and prescription drugs all unchanged. Motor vehicle insurance fell 0.8%, and is down 5.1% over twelve months. Health insurance is down 8.5% on the year. On their weights, medical care services and motor vehicle insurance together removed roughly 0.035 percentage points from the month. Core reached 0.3% with those working against it.

And the part that flatters it. Shelter re-accelerated to +0.3% from 0.1% in July, and on a 35.343% weight that is 0.106pp, a quarter of the entire headline. But rent and owners' equivalent rent both rose only 0.2%. The acceleration came from lodging away from home, which rose 2.4% — and lodging is 1.402% of the index, 4% of shelter's weight, yet produced about a third of shelter's contribution this month. It fell 2.8% in July and 2.3% in June. Hotel rooms bouncing after two down months is not a shelter trend, and shelter is the component the committee watches for persistence.

The same caution applies to the most eye-catching line in the release. Airline fares rose 2.7% seasonally adjusted and are up 23.4% over twelve months — but unadjusted, fares fell 0.5% on the month. The entire monthly increase is the seasonal factor. The twelve-month figure is real and it is enormous; the monthly one is an artifact of how August is normally priced. Yesterday's producer report had passenger transportation up 4.1% on the month and 15.6% on the year, so the annual direction agrees across both sides of the ledger.

Step back to the run rates and the hawkish case gets thinner. Core's monthly path since March reads 0.2, 0.4, 0.2, 0.0, 0.2, 0.3. That single month annualizes to 3.7%. But the three-month annualized rate is 2.0% and the six-month is 2.6%, against a twelve-month rate of 2.4%. Core is not accelerating on any window longer than one month. The headline is noisier still: because June printed -0.4%, the three-month annualized headline rate is 0.4% against a twelve-month rate of 3.4%.

Two more things connect outward. Shelter is running 3.0% over twelve months while yesterday's existing home sales put the median transaction price up 1.6% — owners' equivalent rent lags observed prices by a year or more, so CPI shelter is still importing 2024 and 2025 housing into a 2026 index. And moving, storage and freight expense fell 1.9% on the month and is down 4.6% on the year, which sits oddly against producer transportation and warehousing at +13.0%: freight is expensive for firms and cheap for households.

Food was quiet. The food index rose 0.1%, food at home was unchanged, and food away from home rose 0.3%. Eggs rose 2.9% on the month but remain 23.0% below a year ago. Lettuce fell another 6.2% after 16.4% in July. Beef and veal is up 5.9% over twelve months.

The unadjusted index level is 334.980. CPI-W, which sets the Social Security cost-of-living adjustment, rose 3.5% over twelve months. The chained index rose 3.3%.

The Internals

The four calendar numbers, which is where this release is decided:

Measure · August 2026 · Consensus · July 2026 · Result

CPI m/m, seasonally adjusted · Up 0.4% · Up 0.4% · Up 0.1% · In line

CPI y/y, unadjusted · Up 3.4% · Up 3.4% · Up 3.4% · In line

Core CPI m/m, seasonally adjusted · Up 0.3% · Up 0.2% · Up 0.2% · Hot, and the only miss

Core CPI y/y, unadjusted · Up 2.4% · Up 2.4% · Up 2.5% · In line, and lower

Contribution to the 0.4% headline. Weights are relative importance as of July 2026:

Component · Weight · Monthly change · Contribution · Share of the headline

Core, all items less food and energy · 79.114% · Up 0.3% · 0.237 points · 59.3%

Energy · 7.347% · Up 2.1% · 0.154 points · 38.6%

Food · 13.540% · Up 0.1% · 0.014 points · 3.4%

Of which: gasoline alone · 3.770% · Up 3.9% · 0.147 points · 36.8%

Of which: shelter · 35.343% · Up 0.3% · 0.106 points · 26.5%

Of which: services less energy services · 60.272% · Up 0.3% · 0.181 points · 45.2%

Of which: commodities less food and energy · 18.842% · Up 0.1% · 0.019 points · 4.7%

Core is not accelerating on any window longer than one month:

Window · Core annualized · Headline annualized · Note

One month · 3.7% · 4.9% · August alone

Three months · 2.0% · 0.4% · The headline figure carries June's minus 0.4%

Six months · 2.6% · 4.3% · Carries the March energy spike

Twelve months, reported · 2.4% · 3.4% · Core fell from 2.5%, headline unchanged

The energy block, and why the annual figures matter more than the monthly ones:

Series · Monthly change · 12-month change · Read

Energy, all · Up 2.1% · Up 16.3% · 38.6% of the headline this month

Energy commodities · Up 4.2% · Up 28.0% · The fuel you buy

Gasoline, all types · Up 3.9% · Up 27.4% · Over a third of the headline on its own

Fuel oil · Up 10.1% · Up 52.0% · The diesel pass-through from yesterday's producer report

Energy services · Down 0.4% · Up 4.0% · The meter, and it is calm

Electricity · Down 0.2% · Up 3.8% · Fell on the month

Utility piped gas · Down 1.1% · Up 4.4% · Fell on the month

Shelter, which is 35.3% of the index and the component the committee reads for persistence:

Line · Weight · Monthly change · 12-month change · Contribution

Shelter, total · 35.343% · Up 0.3% · Up 3.0% · 0.106 points

Owners' equivalent rent · 25.918% · Up 0.2% · Up 3.1% · 0.052 points

Rent of primary residence · 7.735% · Up 0.2% · Up 2.7% · 0.015 points

Lodging away from home · 1.402% · Up 2.4% · Up 3.2% · 0.034 points

Tenants' and household insurance · 0.288% · Unchanged · Up 4.1% · Zero

Read the last two rows together: lodging is 4% of shelter's weight and about a third of its contribution, and it had fallen 2.8% in July and 2.3% in June.

Where The Inflation Is

Everything that rose in core, ranked by what it added:

Category · Weight · Monthly change · 12-month change

Shelter · 35.343% · Up 0.3% · Up 3.0%

Airline fares · 1.049% · Up 2.7% adjusted, down 0.5% unadjusted · Up 23.4%

Public transportation · 1.640% · Up 2.3% · Up 15.4%

Motor vehicle maintenance and repair · 1.055% · Up 1.1% · Up 5.2%

Water, sewer and trash collection · 1.145% · Up 0.5% · Up 4.8%

Used cars and trucks · 2.698% · Up 0.4% · Down 2.3%

New vehicles · 3.756% · Up 0.3% · Up 0.6%

Home health care · 0.228% · Up 0.6% · Up 10.6%

Nursing homes and adult day services · 0.221% · Up 0.6% · Up 4.6%

Car and truck rental · 0.162% · Up 2.2% · Up 3.5%

And everything that fell, which is why core at 0.3% understates the underlying month:

Category · Weight · Monthly change · 12-month change

Motor vehicle insurance · 2.563% · Down 0.8% · Down 5.1%

Medical care services · 6.864% · Down 0.2% · Up 2.5%

Dental services · 0.922% · Down 0.6% · Up 5.0%

Health insurance · 0.824% · Down 0.5% · Down 8.5%

Motor vehicle fees · 0.505% · Down 0.7% · Up 1.9%

Moving, storage and freight expense · 0.078% · Down 1.9% · Down 4.6%

Medical care commodities · 1.403% · Down 0.2% · Down 2.7%

Recreation services · 3.154% · Unchanged · Up 2.4%

Apparel · 2.406% · Unchanged · Up 3.6%

The grocery aisle, where almost nothing happened:

Group · Monthly change · 12-month change

Food at home · Unchanged · Up 2.2%

Meats, poultry, fish and eggs · Up 0.1% · Up 1.1%

Eggs · Up 2.9% · Down 23.0%

Beef and veal · Down 1.0% · Up 5.9%

Dairy and related products · Up 0.3% · Down 0.3%

Fruits and vegetables · Down 0.4% · Up 3.2%

Lettuce · Down 6.2% · Down 2.2%

Nonalcoholic beverages · Up 0.2% · Up 3.7%

Coffee · Down 0.6% · Up 6.1%

Food away from home · Up 0.3% · Up 3.4%

Against This Morning's Open

• The Open called the fulcrum exactly, and it resolved hawkish. It said at 06:30: "The fulcrum is core m/m, and it is a one-decimal question... a 0.2% print takes the pressure off, and a 0.3% print, with crude where it has been, is very hard to argue against." It printed 0.3% — The Open.
• It also said "almost nobody will trade" the headline "because the jump is energy and the committee knows it." The headline jumped to 0.4% and gasoline was 36.8% of it, which is that call confirmed on the arithmetic.
• The dollar asymmetry it flagged is the one thing still unresolved. The Open argued DXY had "more room to fall on a soft core print than to rise on a hot one" because the hike was already paid for at roughly 69%. This is the hot print, so the size of the dollar's response is now the live test of that claim rather than its direction.
• One caveat it raised is more important after the fact than before it: "this is an August reading. Brent above $100, the Saudi output loss and this week's escalation all happened in September and are not in it." Energy contributed 0.154pp to this print from prices that have since gone higher.

What This Sets Up

• Next CPI — Wednesday, 14 October, 8:30am ET, covering September. That is the print that first contains Brent above $100 and the Saudi output loss, and on this month's weights energy is already contributing 0.15pp before any of that arrives.
• The read to confirm or break is whether core 0.3% was one month or a turn. The three-month annualized rate is 2.0% and the six-month 2.6%, both below the 2.4% twelve-month rate. A second 0.3% breaks that; a 0.2% restores it.
• Watch shelter without the hotels. Owners' equivalent rent and rent both printed 0.2%. If they stay there while lodging mean-reverts, shelter decelerates next month regardless of what the headline does.
• Watch whether the medical and insurance drags persist. Motor vehicle insurance at minus 5.1% and health insurance at minus 8.5% over twelve months are suppressing core right now. They will not do so indefinitely, and core printed 0.3% with them.

What Is This?

• What it is: The Consumer Price Index measures the change in prices paid by consumers for goods and services, published by the Bureau of Labor Statistics at 8:30am ET. Prices are collected each month in 75 urban areas from about 6,000 housing units and 22,000 retail establishments, then aggregated using expenditure weights. The headline CPI-U covers over 90% of the US population. Alongside it BLS publishes CPI-W, a wage-earner subset that sets the Social Security cost-of-living adjustment, and the chained C-CPI-U, which allows for substitution between goods and is issued in preliminary form.
• Why it matters: It is the inflation number with the most direct line to a rate decision, and this one landed five days before an FOMC at which three officials dissented in July in favor of a hike. It is also the last major data before that meeting.
• How to read it: Read core first and the headline second — energy swings dominate the top line and reverse, which is why the committee looks through them. Then read core against more than one window, because a single month annualizes to something dramatic and usually misleading. And check the weights before crediting any component: a 3.9% move in gasoline matters because gasoline is 3.77% of the basket, while a 2.4% move in hotel rooms matters much less than it looks, because lodging is 1.4%. One more caution specific to CPI: the seasonally adjusted and unadjusted monthly figures can disagree sharply — airline fares rose 2.7% adjusted and fell 0.5% unadjusted this month — so check which one a headline is quoting. BLS puts the standard error on the one-month headline change at 0.04 points, so a 0.4% print is comfortably distinct from zero but not from 0.35%.

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_For informational purposes only. Not investment advice._