That was not a good report from Walmart . While the nation's largest brick-and-mortar retailer reported fiscal second-quarter earnings and revenue that beat analyst expectations, same-store sales only grew by 2.6% compared to last year — well below a FactSet consensus forecast of 3.5%. Mizuho analyst David Bellinger called that comparable store sales whiff "one of the biggest misses in years." Couple that with disappointing earnings guidance for the fiscal third quarter and the full year, and you have what Bellinger referred to as the "worst case scenario" for Walmart. Shares were down 7% in early trading, on pace for their worst day since May 21. The report also raises a major question for the wider stock market: Is consumer spending, one of the key pillars of the economy, starting to slow down? "The slowdown in the funnel challenges the market's bull case," wrote Morgan Stanley analyst Simeon Gutman. WMT 5D mountain WMT 5-day chart Walmart CFO John David Rainey told CNBC that consumers are stretched thin, particularly as energy prices continue to climb. U.S. crude futures are up 53% this year thanks to the U.S.-Iran war. Rainey also said that while Walmart is eligible to receive about $2.9 billion in tariff refunds, Walmart expects to take a roughly $2 billion hit from "incremental cost headwinds related to higher fuel prices this year." "Consumers are still spending, and real wage growth is keeping pace, and so they've been very resilient in this environment," Rainey said . "But all that said, we would love to be able to bring prices down more and see less pressure on their wallets." Combine uncertainty over consumer spending with another increase in oil prices — U.S. crude futures rose more than 2% Thursday to around $88 per barrel — and Treasury yields again moving higher, and you get a downbeat start to the trading day. Dow Jones Industrial Average futures lost more than 400 points, while S & P 500 and Nasdaq-100 futures slid 0.4% and 0.6%, respectively. But ,to be sure, other analysts who cover Walmart remain bullish on the stock. Oliver Chen of TD Cowen, who rates the Bentonville, Arkansas-based behemoth a buy, is "encouraged by WMT's ability to gain share and grow profits faster than sales." KeyBanc analyst Bradley Thomas called Walmart's headwinds "transitory" and reiterated an overweight investment rating. But if those constructive outlooks don't pan out, it could mean trouble not just for Walmart — but for the entire stock market.