Shares plunged as much as 15% on Wednesday after giving a weak holiday-quarter sales forecast that disappointed Wall Street and suggested the chain is barely more immune than rivals like Gap Inc (GPS) and Abercrombie & Fitch (ANF) to young shoppers’ shift away from specialty apparel chains and shopping at malls.

“The retail climate, particularly in malls, is tough and the pace of traffic is choppy. We’re therefore taking a cautious view,” CFO Bob Madore said on a conference call with Wall Street analysts.

American Eagle has outperformed Abercrombie, Gap, and Aéropostale, which recently emerged from bankruptcy protection as a smaller chain, for several years now. But its forecast for comparable sales to be flat or increase by a modest, low-single-digit percentage in the fourth quarter was not good enough for investors.

The company has gotten kudos for its denim assortment and lower reliance on discounting than rivals. But markdowns at American Eagle were up last quarter. And that is likely to continue, analysts said.

“The American Eagle brand ran earlier and deeper promotions during Black Friday and Cyber Monday,” Wolfe Research analyst Adrienne Yih wrote in a research note. “We believe AEO will continue to run elevated promotions throughout [the fourth quarter] to drive traffic but will result in lower quality sales.”

In other words, expect American Eagle’s profit margin to take a hit. The company expects a fourth-quarter adjusted profit of 37 cents to 39 cents per share, well below analysts’ average estimate of 45 cents, according to Thomson Reuters I/B/E/S.

Last week, Abercrombie & Fitch, which also owns the Hollister brand and is in the midst of trying to reinvent its flagship brand, said holiday-quarter sales would be challenging. And Gap Inc expects more shopper traffic woes, suggesting that mall-based clothing stores will have another tough holiday season.

But all hope is not lost for American Eagle: Comparable sales of its Aerie youth lingerie brand rose 21% during the quarter. And Cowen & Co analyst Oliver Chen said the company could win some market share from the stores Aéropostale has closed.

American Eagle as a whole reported a smaller-than-expected 2% in quarterly comparable sales, which exclude the impact of new or newly closed stores, for the third quarter. Net revenue rose 2.3% to $940.6 million, in line with the average analyst estimate. American Eagle’s net profit rose to $75.76 million, or 41 cents per share, from $74.11 million, or 38 cents per share, a year earlier.