When Macy’s, a store closely associated with Christmas, says there is trouble brewing ahead of the holidays, it is enough to send the world of shopping into a tailspin.

The retailer of "Miracle on 34th Street" warned Wednesday that its stores were awash with merchandise after a sluggish fall season and that slow business would force it to go all-out on discounts during the holidays.

Macy’s shares plunged about 14 percent, dragging other retailers down, too. The Hudson’s Bay Co., which owns Saks Fifth Avenue and Lord & Taylor, fell 5 percent, as did Kohl’s. Burlington Stores fell about 7 percent.

"We’re clearly disappointed," Terry J. Lundgren, Macy’s chief executive, said in a call with investors. "We believe the retail industry is going through a tough period. We seem to experience something like this every five to seven years or so."

Aggressive discounting from one of the country’s biggest merchants is bad news for retailers this holiday sales season, which is shaping up to be highly discount-driven. It also raises questions about the strength of the economic recovery, and of consumer sentiment.

But a shift in the way Americans shop because of the proliferation of e-commerce, and the power to compare prices at a click of the mouse, has meant that a brightening economy is no longer a tide that raises all retailers, said Oliver Chen, a retail analyst at Cowen.

"The only tide that’s raising all ships is online and mobile," Chen said.

Still, the outlook for some merchants is better, analysts say. Winners, and losers, are emerging.

Retailers that go head-to-head in the mall with Macy’s are likely to take a hit from its heavy promotions, including J.C. Penney, Gap and Kohl’s, said Paul Lejuez, a retail analyst at Citigroup.

But off-price stores like Ross Stores or TJX, which runs T.J.Maxx and Marshalls, are expected to do well again this year as "treasure hunting" for rock-bottom deals on national brands becomes the norm. These off-price businesses also source their wares from retailers with excess inventory.

Overall, the National Retail Federation, a trade group, predicts sales in November and December will rise 3.7 percent to $630 billion, slightly under last year’s 4.1 percent gain.

Another retailer looking to prove itself is Wal-Mart, which announced its holiday plans on Wednesday. Its Black Friday deals will begin in stores at 6 p.m. on Thanksgiving Day, the same time as last year. Online deals are available at 3 a.m. Eastern time.

Once laser-focused on price, Wal-Mart has been investing in wage increases for its workers, and in improving stocking and presentation to try to revamp the shopping experience in its stores.

So while Wal-Mart is offering so-called doorbusters — a Samsung curved 55-inch, 4K flat-screen TV for $999, for example — a focus this holiday season will be execution, Wal-Mart’s U.S. chief executive, Greg Foran, told reporters.

For Wal-Mart, that means stocking up to avoid shortages on the most popular products — more than a million TVs, and more than 10 million pajamas — as well as helping shoppers navigate the store with an integrated shopping app, and speeding up the checkout process.

Simplicity is a big theme this year, Foran said. Almost all deals available in stores will be available online.

"There’s nothing more frustrating than getting to the store in search of a deal and finding out: Gee, how many did the store have? Just four of them," Foran said.

Chen said Wal-Mart would benefit this holiday season because of the breadth of its offerings, like pharmacy products and electronics, which makes it less dependent on winter fashion and the weather.

Still, all retailers are fighting another big shift for the American consumer: away from buying things, period.

"The big issue is what are consumers spending money on?" Lejuez of Citi said. "They’re spending it to eat out, they’re spending it on iPhones, on Netflix and Spotify," he said.

"The consumer is fine," Lejuez said, "but retailers are not."

© 2015 The New York Times Company