Walmart experienced the slowest growth in U.S. comparable sales in six years during its most recent quarter and it offered a cautious outlook for the year, sending company shares down 6% before the opening bell Thursday.

Comparable sales in U.S. stores, which measure sales at stores open at least a year along with online sales tied to those locations, rose 2.6% in the second quarter. They rose 4.1% in the previous quarter.

Excluding the wellness category that includes Walmart’s pharmacies, comparable sales increased 3.4% in the second quarter. Those sales were hit by federal legislation that requires pharmacies to dispense some high‑cost Medicare drugs at capped prices, the retailer said. That was still below analysts’ projections of a 3.8% increase, according to FactSet.

Walmart’s U.S. e‑commerce business, which has become an engine of growth for the retailer, rose 24%, trailing the first‑quarter pace of 26%.

Walmart is among the first batch of major retailers to report second‑quarter results, which could offer industry analysts and economists another read on whether ongoing price pressures from the conflict in Iran have impacted consumer behavior.

Walmart is considered a barometer of consumer spending given its vast customer base. More than 150 million customers are on its website or in its stores every week, according to Walmart.

That may draw even more attention this quarter after U.S. data released Friday showed that retail sales were surprisingly weak in July and a new read on consumers from the University of Michigan revealed growing pessimism about the economy, with so many Americans struggling with higher costs for gas, groceries and just about everything else.

The new figures from Walmart revealed the smallest gain in comparable store sales since a 1.9% gain for the quarter ended Jan. 31, 2020, according to FactSet.

That has broadened Walmart’s customer base and the retailer has begun capturing a larger share of wealthier Americans. The biggest gains in market share for Walmart are coming from households with annual incomes over $100,000.

Walmart’s quarterly net income was $6.37 billion, or 80 cents per share, in the three‑month period ended July 31. Adjusted per‑share results were 81 cents, easily topping the 74 cents Wall Street had expected, according to FactSet.

Sales rose 5.9% to $187.94 billion. Analysts were predicting $186.62 billion, according to FactSet.

For the third quarter, Walmart expects earnings per share of 62 cents to 64 cents. It projects sales to be up 3% to 3.5%. That would put sales in a range of $184.88 billion to $186.23 billion. The forecasts are below analysts’ expectations of 68 cents per share and sales of $188.19 billion, according to FactSet.

For the full year, Walmart now expects earnings per share to be in the range of $2.80 to $2.87 while sales should be up anywhere from 4% to 5%. That would mean a forecast for sales in the range of $741.7 billion to $748.8 billion, according to FactSet.

Analysts expected $2.90 per share and sales of $752.06 billion for the year, according to FactSet.