Here are the actions that worry most Wall Street if a full-blown trade war breaks out

It would take two tweets from President Donald Trump to shake the markets, and these companies could be the hardest hit.

Trump threatened Sunday to raise tariffs on products imported from China, which immediately shook the stock market, whose profits and hopes of trade agreements were better than expected. If the threat materializes, companies with high incomes in China, including suppliers and retailers of semiconductors, would probably be the main victims, according to Wall Street analysts.

HSBC is consistent with the list of the most tariff-sensitive companies registering significant sales in China. US companies with a strong presence in China are concentrated in the technology sector, including Skyworks Solutions, Broadcom, Micron Technology and Intel.

Some on the list are already taking a hit. Apple's shares fell nearly 2% on Monday as shares of Nvidia fell 3.4%.

"Quinn Bolton, "Semiconductor Providers Have Relatively High Exposure to Revenue from Goods Delivery" in China. senior semiconductor analyst in Needham, said in a note on Monday. "This strong exposure to China further exposes the semiconductor industry to the escalation of the US-China trade war than many other segments of the technology."

Bolton highlighted MaxLinear, Ambarella, Monolithic Power Systems and Semtech, which account for over 50% of their sales in China based on their results for 2018 or 2019. The Vaneck Vestors Semiconductor ETF is down 2.6% on Monday. , on the verge of affirming its worst day since March 22.

According to Michael Lasser, Equity Analyst at UBS, some retailers may also be under pressure because high tariffs would drive up costs for the imported products they sell.

"If the shift to 25% tariffs materializes and persists for a long time, we think the impact on many consumers, retailers and food retailers would be considerable," Lasser said in a note on Monday. "The 25% tariffs charged would be rather inflationary, with retailers indicating that they would use strategic price measures, to the extent possible, to mitigate the impact."

The analyst said furniture retailers, Bed Bath & Beyond, William-Sonoma and Restoration Hardware, could pose "significant risk" because of their high exposure to products from China.

– CNBC Michael Bloom Contributed reports.