Illumina Inc. (ILMN) shares experienced a significant 5.06% plunge in the 24-hour period leading up to the close of the pre-market trading session on Tuesday, February 4th. This sharp decline in the biotechnology company's stock price appears to be driven by escalating trade tensions between the United States and China, as well as China's decision to add Illumina to its "unreliable entity list".

Amid the ongoing trade dispute between the two economic superpowers, China imposed retaliatory tariffs on various U.S. goods, including a 15% levy on coal and liquefied natural gas exports, and a 10% tariff on crude oil and agricultural machinery. This move came swiftly after President Donald Trump implemented a 10% tariff on all Chinese exports to the U.S., citing concerns over illegal drug trafficking.

In a separate but related development, China's Commerce Ministry announced that it had placed Illumina, along with apparel company PVH Corp., on its "unreliable entity list". This decision was attributed to allegations that these companies had taken "discriminatory measures against Chinese enterprises" and "damaged" the legitimate rights and interests of Chinese companies. The inclusion on this list could potentially lead to sanctions or other punitive measures against Illumina within the Chinese market.