President Trump's escalating trade war is especially bad news for a number of U.S. companies that have significant sales in the Chinese market. According to Barron's, stocks that are in particular danger if the trade war expands include these six large caps: Archer-Daniels-Midland Co. (ADM), Deere & Co. (DE), Nike Inc. (NKE), Apple Inc. (AAPL), Yum! Brands Inc. (YUM), and Starbucks Corp. (SBUX). 

All six of these stocks plunged with the S&P 500 (SPX) on Thursday, and their mixed results today illustrated continued uncertainty about the scope and impact of a trade war. As of 2:45pm trading on the NYSE: Apple, Deere and Starbucks were down 1 percent or more, Yum! Brands was unchanged, and Nike and Archer-Daniels-Midland were up as much as 2 percent.

Investors' concern is that China will retaliate with its own trade barriers due to the President's plan to impose tariffs on as much as $60 billion in Chinese products. China launched the opening salvo with plans to impose tariffs on about $3 billion in American goods. The level of that concern is illustrated by a CNBC Fed Survey in which 66% of respondents say that President Trump's trade policies are bad for economic growth. The respondents included economists, fund managers, and strategists.

Trade War Backlash On Stocks

Part of China's response, should Trump make good on his tariff threat, might be to import less food from the U.S., turning to other nations instead. David Riedel, who heads independent equity research firm Riedel Research, indicates in a note cited by Barron's that Archer-Daniels-Midland, a leading processor of U.S. farm commodities, as well as farm equipment maker Deere, could be among those U.S. companies that are damaged. The bigger picture is that China is the second-largest market for U.S. farmers, buying over $21 billion of U.S. agricultural products in 2016, CNBC reports.

Encouraging Consumer Boycotts

"Beijing has a long history of initiating or supporting consumer boycotts in support of national objectives," Riedel writes in that note, as quoted by Barron's. That's why various U.S. consumer brands that have gained ground in China may be at risk. These include athletic apparel maker Nike, computer and smartphone maker Apple, fast food operator Yum! (the parent of KFC, Taco Bell, and Pizza Hut), and coffee shop chain Starbucks. Sales of Japanese cars fell precipitously in China in the wake of 2012 tensions over island claims, Riedel indicates, though they recovered a few quarters later.

Industries in Danger

Credit Suisse has noted that the American auto, industrial, and retail industries will suffer in a trade war - affecting a large number of major U.S. stocks - because they are highly dependent on global supply chains. The result is bound to be a combination of rising input costs, due to tariffs, and possibly also supply restrictions. Meanwhile, as with Deere, retaliatory tariffs, import restrictions, or boycotts initiated by China will weigh heavily on U.S. auto and industrial exports to that market. While Credit Suisse believes that U.S. tech companies generally will weather the storm, Apple is a prime example of one that may take a hit. (For more, see also: Why Techs, Banks May Outperform In a Trade War.)

In addition to U.S. farms, with $21 billion of exports to China in 2016, CNBC names the next four biggest targets for retaliation by China. These are, with their 2016 exports to China: aircraft, $15 billion; electrical machinery, $12 billion; machinery, $11 billion; and vehicles, $11 billion.

U.S. Jobs at Risk

Data from the U.S. Department of Commerce cited by CNBC indicates that about 910,000 jobs in the U.S. are supported by exports to China, 600,000 in goods and 310,000 in services. On Sunday, 45 trade associations that include a number of major U.S. companies sent a letter to President Trump warning that tariffs on imports from China would increase consumer prices, cause job loss, and damage stock prices, CNBC adds.

Top Wall Street Fear

"The balance of risk for equities has moved from the Fed to the White House," writes Art Hogan, chief market strategist at B. Riley FBR, as quoted in another CNBC story. He was commenting on the recent CNBC Fed Survey, in which 75% of respondents (who include economists, fund managers, and strategists) say that they worry about a trade war, and while 66%, as mentioned, said that President Trump's trade policies are bad for economic growth. Regarding NAFTA, 80% of those surveyed say that leaving the agreement would be negative for the U.S., with 48% indicating that it would be very negative.