New vehicles are piling up on U.S. car lots, creating concern just as sales are expected to sputter.

The inventory of unsold new cars on dealer lots rose 2.1 percent last month, setting an all-time February high, a top industry analyst said in a research note this week. That total of 4 million new vehicles in U.S. stock is a 21-month high, Morgan Stanley’s equity analyst Adam Jonas wrote. In dollar terms, it’s about $140 billion in inventory, Jonas wrote.

That and other economic concerns have analysts worried the second half of this year won’t be as good for carmakers as hoped.

“The rising inventory despite stalling sales trend is of particular concern to us given market expectations of a significant second-half recovery in earnings for many of our U.S. names,” Jonas wrote.

The slowing sales and high inventory will affect General Motors, Ford and Fiat Chrysler Automobiles in different ways. Jonas said GM exhibits likely the strongest in a first- to second-half earnings growth, with minus 15 percent earnings per share shifting to plus 14 percent. Jonas thinks Ford’s earnings per share will move from minus 20 percent compared with last year in the first half to up 7 percent in the second half. But Jonas warned, “FCA’s second-half earnings per share (is expected) to fall 18 percent year over year, growing 6 percent year-over-year in the first half.”

Jonas said his Detroit 3 forecasts depend on profits in China, the world’s largest car market, recovering and improving from a weak 2018.

Jon Gabrielsen, an economist and consultant to the auto industry, offered a contrary view. He noted that GM and Ford have been continuously losing market share for at least a decade, whereas “FCA has been gaining market share for the same period.”

“This FCA will be larger in the coming recession than in the past while GM and Ford will be smaller in a recession than they were in the past. The less scale you have in a recession the more your earnings (loss) suffer,” he said.

Other economists said that if President Trump enacts tariffs, that could lead to higher new car prices, killing consumer appetite and inflating stock on lots to even greater levels.