September CPI runs 3.7% against 3.6% expected, with core at 2.6% and gasoline up 9.1% in the month

Consumer prices rose 0.6% in September and 3.7% from a year earlier, the Bureau of Labor Statistics reported Wednesday. The monthly figure matched the consensus forecast, but the annual rate was a tenth above the 3.6% economists expected and up from 3.4% in August, according to CNBC and Fox Business.

Core prices, which leave out food and energy, rose 0.3% on the month and 2.6% on the year. Both were a tenth above forecast (0.2% and 2.5%), and the annual core rate is up from 2.4% in August.

The number behind the number

Energy did most of the work. CNBC reported that the energy index rose 5.2% in the month and that gasoline, up 9.1%, accounted for about half of the headline gain. Food was flat on the month and up 2.5% on the year. Shelter rose 0.4% and used cars and trucks 0.7%.

Two things are easy to miss. First, the miss was not only fuel: core was hotter than expected too, so this is not a pure gasoline story that fades when pump prices ease. Second, the monthly core pace of 0.3% is the same as August's, so the acceleration in the annual core rate comes from the base a year ago, not a sudden jump this month. The calendar on our calendar page shows the next CPI release on November 10.

What the market did

CoinDesk reported the 10-year Treasury yield jumping 9.3 basis points to 5.308% and the 2-year up 13.1 basis points to 4.924% after the release, with Nasdaq 100 futures down 0.65%, S&P 500 futures down 0.3% and gold down 1.5% to $4,116 an ounce. Bitcoin dropped about $1,000 to roughly $82,800.

Before the data, CoinDesk noted, Fed speakers had signalled a likely 25 basis point hike before year-end, with markets mostly expecting a pause at the October 28 meeting and a hike in early December. It added that this report "just might put an October rate hike back on the table." That is one outlet's read of pricing, not a Fed decision. The Fed has not changed anything today.

Who it actually hits

On Monday we worked these three examples at the forecast. Here they are at the actual numbers. Substitute your own figures.

The tenant with a CPI escalator

A shop paying $6,000 a month under a lease that follows the all-items year-over-year CPI faces 3.7% of $6,000, or $222 more a month, $2,664 a year. If the clause followed core at 2.6%, it would be $156 a month, $1,872 a year. The index named in the clause is worth $792 a year. Check which month it reads and whether there is a cap.

The employer matching inflation on payroll

Eight staff at $48,000 each is a $384,000 payroll. A raise matching 3.7% is $14,208, plus 7.65% employer payroll tax of about $1,087, so roughly $15,295 a year. Matching 2.6% would be $9,984 plus $764, about $10,748. The $4,547 difference is the cost of deciding whether you are chasing the headline or the underlying trend.

The fuel-heavy service contractor

A landscaping, HVAC or delivery business with $250,000 of annual service contracts and a $150,000 cost base that rises 3.7% with prices fixed loses $5,550 of margin, 2.22% of revenue. Fuel moved far more than 3.7% this month, so a fleet business is likely to be running worse than that average. Pull your own fuel line before you trust any national figure.

What to actually do

• Do not reprice off the headline. Take your own last twelve months of fuel, wages and supplier invoices and apply each line's actual change. That number belongs to your business.
• If you carry a floating-rate line, do nothing today but know your exposure. Whether the Fed moves on October 28 is not settled by one report. Work out what 0.25 point costs you on your drawn balance so the number is ready.
• If you raise prices, do it once and explain it. See our guide on raising prices.

Related: what Wednesday's 3.6% CPI forecast means for a tenant, an employer and a contractor, and our tracker on the 2027 Social Security COLA, which uses this same index.

Sources: Bureau of Labor Statistics Consumer Price Index; CNBC and Fox Business reports of the release; CoinDesk for market moves; Chronicle economic calendar for forecasts and dates. Market figures were taken shortly after the 8:30 AM ET release and move through the day. This is market information, not investment advice.