Amid a tumultuous day for U.S. stocks, AAPL ended down 7.9%, but it wasn’t the only big tech company to sink. As detailed by CNBC, big tech companies lost over $320 billion in value today, coinciding with the worst day for broader market since 2008.

As we explained this morning, the market slump is driven by two factors: coronavirus concerns and oil prices.

For Apple specifically, the ongoing coronavirus situation is a major concern for investors. An investor note earlier today estimated that Apple sold less than 500,000 iPhones in China during February, down 60% compared to the 1.27 million units sold in the same month a year ago. Supply of iPhones and other Apple products is also starting to run low around the world.

Second, and the specific trigger for the current concern, Saudi Arabia slashed oil prices over the weekend, with immediate impact on energy companies, then banks due to concerns that energy firms could default on loans, and the rest of the market as a knock-on effect.

Meanwhile, Bank of American analysts expect that the 5G iPhone and iPhone 9 launches will be delayed this year due to the disruptions caused by coronavirus. Apple also recently told many of its employees to work from home this week and detailed other anti-coronavirus measures.