There is good news in the lone economic report of the shutdown: Inflation was benign in September, with little sign tariffs are igniting a nationwide price shock.

Why it matters: Within months, tariffs rose to the highest in a century — yet companies so far are holding the line on consumer prices in ways few outside of the White House expected.

• "Much like a Sherlock Holmes story, inflation is the dog that didn't bark," Chris Zaccarelli, chief investment officer at Northlight Asset Management, wrote in a client note.

By the numbers: The shutdown-delayed report showed that the Consumer Price Index and the core measure that strips out food and energy costs rose 3% in the 12 months through September.

• Economists expected that the overall CPI would rise more from the 2.9% in August.
• Core CPI actually ticked down.

Zoom in: The report shows that disinflationary trends were intact in the housing sector, a massive category in the CPI that has kept upward pressure on overall inflation.

• Shelter rose just 0.2% in September, down from the 0.4% increase the prior month. Owners' equivalent rent — how the BLS measures inflation for homes that people own — saw the smallest price increase in almost 5 years.

The big picture: The report amounts to a bright green light for the Fed to cut interest rates for the second time this year following its two-day policy meeting that ends on Wednesday, and tilts things toward an additional cut in December.

• "This will be framed as an insurance cut, with hopes that by December the shutdown is over and the Fed has a clearer read on jobs," Fitch Ratings economist Olu Sonola wrote, noting that tariff passthrough to consumers "generally remains muted."

Yes, but: Inflation is still uncomfortably high for Fed officials. Over the last three months, core CPI is up an annualized 3.6%, compared to the 3.1% rate in the same period a year ago.

Between the lines: Americans likely still feel sticker shock with many expenses, with no guarantee that tariff-related price increases will remain moderate.

• Retail coffee prices are up 19% compared to a year ago, at least in part because of President Trump's tariffs.
• Utility prices fell in September, but are up nearly 12% over the past year.

The bottom line: The cooler-than-expected inflation report offered a small window into the economy's health last month.

• Economic policymakers won't get much more information for some time, as the government shutdown drags on and delays key reports.

Social Security recipients will receive a 2.8% bump in January in their annual cost of living adjustment, determined in part by this morning's CPI number.

By the numbers: That surpasses a 2.5% rise this past January, and will apply to both 71 million Social Security beneficiaries and 7.5 million Supplemental Security Income recipients.

• The average Social Security retirement benefit is $1,955 a month this year, so that will rise by about $54 a month.
• The average Social Security disability insurance payment is $1,446 a month, so that will rise by about $40.

Of note: As part of the same inflation adjustment process, the wage threshold above which workers owe no Social Security tax increased. It will be $184,500 in 2026, up from $176,100.

State of play: The COLA is based on the Consumer Price Index for the July through September quarter, compared with a year earlier.

• Therefore, the September report is the final data point needed to complete the arithmetic.
• The Bureau of Labor Statistics brought in furloughed workers to complete the CPI report because of this urgency.