Everyone is waiting for Friday’s big inflation report. Here’s what you can expect

September’s Consumer Price Index report, released on Friday, is about the only game on the data-hungry Wall Street this month and is increasingly likely to be a market-moving event.

The actual numbers are expected to be about the same level as in recent months, but given the lack of official economic reporting due to the government shutdown, even small deviations could have a huge impact.

“We haven’t had any recent government statistics, so all the market attention and market attention is going to be on this one report,” said Troy Rutka, senior U.S. economist at SMBC Nikko Securities. This concludes all reports.

But as far as Wall Street consensus is concerned, the Bureau of Labor Statistics’ CPI release appears to be about the same.

Economists surveyed by Dow Jones expect the monthly all-in-one data to rise 0.4%, unchanged from last month, and for 12-month inflation to rise 3.1%, or 0.2 percentage points above August levels. Core CPI, which excludes food and energy, is expected to rise 0.3% month-on-month and 3.1% annually, both at the same level as August. This is the highest annual rate since January.

What the streets are watching are deviations in readings that indicate inflation is rising or falling more than expected. There will also be a focus on details of how President Donald Trump’s tariffs are affecting prices.

The report, which had been scheduled for release on October 15, would be the last major economic data before the Fed’s policy meeting, which concludes on Wednesday. The BLS called back the workers because it uses CPI as a benchmark for Social Security cost-of-living adjustments.

Economists at Goldman Sachs expect car prices to remain largely unchanged, with auto insurance prices rising and airfares falling. On the tariff issue, the company said in a note that it expected “upward pressure” in categories such as communications, home furnishings and recreation, but that the increase to core inflation would be only 0.07 percentage points.

But with many government agencies closed, data is generally a black box, raising questions about the reliability of the CPI.

“We’re not entirely clear on the lack of important data points that markets rely on due to the government shutdown,” said Vishal Khanduja, head of broad-market fixed income at Morgan Stanley Investment Management. “So there’s more uncertainty.”

In fact, investors have been on edge lately, pushing average prices in major stock markets to near record levels, despite continued volatility on a daily basis.

Geopolitical uncertainty is a source of concern, with the ever-changing tariff landscape raising concerns that rising prices will slow the pace of economic growth that has been surprisingly strong. The CPI report should help answer at least some of these questions, despite concerns about how clean the data will be due to shutdown-related disruptions.

This is true for both markets and the Fed, which holds a policy meeting next week where officials are widely expected to approve another quarter-point rate cut.

“In terms of market impact, it would take a meaningful surprise on the upside for the market to change its mind about further rate cuts,” said Julien Lafargue, chief market strategist at Barclays Private Bank.

Barring frequent fluctuations due to trade wars, another strong earnings season is lifting the market. Pre-lockdown economic data also showed the economy was surprisingly resilient, with gross domestic product (GDP) hitting nearly 4% in the third quarter, according to the Atlanta Fed.

Some outcome is needed to shake up this narrative, and a surprise from CPI could be just that.

“If the numbers are better than expected, you’re going to see more volatility,” said Stephanie Link, chief investment strategist at Hightower Advisors. “With the economy strong, the Fed starting a rate cut cycle, double-digit EPS growth, and the fourth quarter being seasonally the strongest quarter of the year, I see this as a buying opportunity.”