Stocks plunged Monday as bellwether Caterpillar got a busy earnings week off on a down note, missing profit expectations and adding to worries of a 2019 slowdown.

The Dow Jones industrial average dropped more than 200 point points, or 0.8 percent, on the news. Caterpillar is a heavy equipment giant and a big Dow component. Its shares were down almost 10 percent. 3M, Visa and Microsoft were other drags on the Dow.

Technology company Nvidia added to the downward market spiral by cutting guidance due, in part, to deterioration in China sales. Nvidia lowered fourth-quarter guidance Monday, saying revenue is expected to be $2.2 billion, down from $2.7 that it had previously estimated.

The Standard & Poor’s 500-stock index was down 0.8 percent. The tech-heavy Nasdaq composite was struggling as well, dropping 1.1 percent.

Energy companies were down on a drop in oil prices.

Caterpillar was also less optimistic for 2019 than analysts had assumed, a sign that it may see the global economy slowing.

“Cat is a bellwether of global economic activity,” said Ed Yardeni, president of Yardeni Research. “Its latest earnings report confirms lots of other indicators showing the global economy is slowing down.”

Caterpillar is the world’s largest maker of earth-moving equipment and a harbinger of global economic health. Its products service a wide swath of industries, including road construction, petroleum, mining, logging and agriculture.

The Peoria, Ill.-based company, with more than $50 billion in revenue and 95,400 employees, is a major consumer of steel and other materials, which it uses to make tractors, truck engines and loaders.

Caterpillar reported earnings of $2.55 per share, well under the $2.99 per share analysts were predicting.

Caterpillar said tariffs were raising steel prices and cutting into profits.

President Trump’s steel tariffs have raised steel prices for U.S. companies, although the president said in a tweet on Monday that the tariffs have revived America’s steel industry:

“Tariffs on the ‘dumping’ of Steel in the United States have totally revived our Steel Industry. New and expanded plants are happening all over the U.S. We have not only saved this important industry, but created many jobs. Also, billions paid to our treasury. A BIG WIN FOR U.S.”

The company said it had a record 2018, with full-year sales and revenue at $54.7 billion, up 20 percent from $45.5 billion in 2017. Caterpillar’s guidance for 2019 profit was weaker than expected. It said it expects 2019 profit to increase to a range of $11.75 to $12.75 per share. Analysts had expected $12.73 per share.

The company’s revenue beat expectations, earning $14.34 billion for the fourth quarter of 2018 compared with $14.33 billion that analysts expected. But Caterpillar’s chief executive was cautious about 2019.

“Our outlook assumes a modest sales increase based on the fundamentals of our diverse end markets as well as the macroeconomic and geopolitical environment,” chief executive Jim Umpleby said in a statement accompanying the earnings.

Caterpillar’s early report on Monday launches the busiest week of the earnings season, with key players including Facebook, Amazon, Apple, Microsoft, McDonald’s, Pfizer and others set to report earnings this week.

A healthy week could foretell less volatility in the stock market. Disappointing earnings are likely to lead to more volatility similar to that seen in 2018.