Tiffany & Co. Christmas Lights on 57th Street and 5th avenue in New York.Manhattan Christmas Decorations, New York, USA - 07 Dec 2018

Count Tiffany & Co. and Nordstrom Inc. as canaries in the luxury coal mine.

Both the jeweler and the tony department store showed signs of a high-end withdrawal in the U.S., reporting holiday sales slowdowns.

After a year of “robust” U.S. spending, Tiffany chief executive officer Alessandro Bogliolo told WWD on Friday that domestic shoppers “really paused” during the holiday season.

The Chinese dynamic stayed the same, with customers spending less while they travel, but boosting consumption at home, where Tiffany is building its exposure.

But the picture was different — and new — at home.

Tiffany’s global net sales fell 1 percent to $1.04 billion for November and December combined while comparable sales declined 2 percent. (By both measures, sales were flat adjusting for currency fluctuations).

That amounts to something of a splash of cold water for Tiffany after global net sales rose 10 percent in the first three quarters, or 7 percent on a comp basis.

“The positive trend went down,” Bogliolo said. “It came as a bit of a surprise to us. We were expecting the very positive trend to continue, maybe not as strong as the first 10 months of the year. It’s hard to say exactly what happened. But personally, I think it’s all this uncertainty, these external events, the market.”

Wall Street started showing signs of serious weakness in the fall as the election, the reality of divided government, the trade war and signs of slowing in China and more threatened stocks. The Dow Jones Industrial Average showed a strong gain Friday, rising 336.35 points to 24,706.35, but has fallen has fallen 7.9 percent since Oct. 3, when it neared 26,900.

Bogliolo suggested consumers in the U.S. were feeling less wealthy over the holidays.

“We have seen it, of course, in Europe,” he said. “Europe is more understandable if you consider the Brexit, that is somehow more obvious.”

And Tiffany isn’t alone.

Nordstrom said earlier in the week that its full-price comps inched just 0.3 percent since its fourth-quarter began in early November — a sharp deceleration from the 1.9 percent rise seen in the first three quarters.

The company attributed the drop-off to “softer traffic in the stores.”

The implications caused more than a little consternation.

UBS analyst Jay Sole described Nordstrom’s traffic decline as “unexpected and broad-based step-change drop lower in December.”

“The pivotal question is why this occurred,” Sole said. “Our impression is typical culprits such as weather, tourism, fashion, and operational execution were probably not issues. Perhaps we are simply witnessing another chapter in the story of consumers leaving the mall to shop online. If so, this would severely damage our buy thesis which hinges on the idea Nordstrom’s full-price stores will serve a useful purpose in the future.”

But separate UBS research suggests high-end spending was relatively weak last month generally. “Stock market volatility can often dampen high-income consumer spending,” he said. “We want to see more results from softline companies who serve high-income consumers” before deciding on Nordstrom.

The spending picture should become more clear as other high-end retailers, such as Neiman Marcus and Saks, reveal results.

But it might be time for luxury retailers — really all retailers — to be watchful of consumers and flexible in their own operations.

Alessandro BoglioloTiffany Blue Book Collection: The Four Seasons of Tiffany jewelry collection launch, Arrivals, New York, USA - 09 Oct 2018

Tiffany & Co.’s Alessandro Bogliolo  Stephen Lovekin/REX/Shutterstock

Bogliolo, who joined Tiffany last year and set a six-point plan to rejuvenate the business, is walking something of a tightrope, looking to invest in and grow the business at the same time.

Tiffany has projected a low-single digit increase in sales and a mid-single digit rise in profits for the year ahead.

“We will have an agile approach to things,” he said. “We have to keep on surprising the consumer. I am very bullish, but I have to moderate these expectations because of these uncertainties I see in the world and also in our domestic market.

“Our industry is very capital intensive,” Bogliolo said. “We have committed to big projects hundreds of millions of investment [dollars]. These hit the profitability in the short-term, you have to spend money. We have to compensate for this increased expense by being more efficient.”