Tech stocks plummeted on Thursday, with Apple (AAPL) leading “Magnificent Seven” names lower following President Trump’s reciprocal tariff announcement the day prior.

Shares of Apple notched their worst day since March 2020 after the stock cratered over 9%, erasing over $310 billion from its market cap. The largest risk, according to analysts, centers on the iPhone maker’s overseas production hubs, which are particularly vulnerable to the tariffed countries.

Read more about Apple’s stock moves and today’s market action.

On Wednesday, Trump announced tariffs that will impact some 185 countries, including the United States’s largest trading partners. Additional reciprocal tariffs, for instance, will include 34% tariffs on Chinese imports, a 20% tariff on European Union imports, a 46% tariff on imports from Vietnam, 32% on imports from Taiwan, and 26% on India — all set to take effect on April 9.

Notably, the additional 34% tax on China will be added to the country’s existing 20% tariff, meaning its total tariff rate will rise to 54%. China is Apple’s most important production hub, with about 85% of its iPhones manufactured there.

“Apple produces basically all their iPhones in China, and the question will be around exceptions and exemptions on this tariff policy if those companies are building more operations, factories, and plants in the US like Apple announced in February,” Wedbush analyst Dan Ives said in a note to clients following the announcement.

As trade tensions escalate, Apple has moved to increase its supply chain beyond just China, boosting manufacturing in places like India and Vietnam. But with the new tariff announcements set to impact those countries too, there’s now limited room for reprieve.

“The worry will be around pricing and margin impacts along with what this means for the global supply chain looking forward,” Ives said. For now, the analyst continues to believe major negotiations will happen over the coming months as companies attempt to navigate “this new world of tariffs.”

Until then, he warned, “tech stocks will clearly be under major pressure.”

Other Magnificent Seven players also faced significant selling action. In aggregate, that cohort of stocks eliminated over $1 trillion from their collective market caps, according to Bloomberg data analyzed by Yahoo Finance.

At the close, Amazon (AMZN) and Meta (META) each fell around 9%, matching Apple, followed by an 8% drop in shares of Nvidia (NVDA) and a 5% decline in Tesla (TSLA). Alphabet (GOOGL) fell 4% while Microsoft (MSFT) was off over 2%.