San Francisco CNN Business  — 

Apple re-entered bear market territory in the midst of Monday’s market sell-off, which was sparked by worries over an escalating trade war between the United States and China.Its shares were down 5.81% on the day and are off roughly 20% from a high of over $233 in October.

Shares closed at $185.72 and continued to fall in after-hours trading. The S&P 500 fell 2.4% on the day and the Nasdaq dropped 3.4%.

Apple (AAPL) has been trying to regain its footing in China. In its most recent earnings, released April 30, the company posted revenue of $10.2 billion in the country for the first three months of the year, down 21% from a year earlier. On a call to discuss the results, CEO Tim Cook signaled that the worst may be over for sales of theiPhone, its biggest profit generator, as Apple (AAPL) saw “improved trade dialogue” between China and the United States and “very positive customer response to the pricing actions we’ve taken in that market.”

Then on May 5 President Trump warned that he would increase tariffs on a bundle of Chinese goods to 25% from 10%. Apple shares have fallen more than 10% since then.

The latest round of tariffs between the two countries has taken a toll on Apple shares, as well as those of companies that provide components for Apple products. Shares in Catcher Technology, a Taiwanese company that makes iPhone cases, dropped nearly 7%. Austria’s AMS (AMSSY), which makes light sensors, plunged more than 5% and shares in European chipmakers Dialog Semiconductors (DLGNF) and STMicroelectronics (STM) dropped 5% and over 6%, respectively.

The drop also comes the same day that the Supreme Court ruled a group of iPhone owners who accuse Apple of violating US antitrust rules can sue the company.