What happened

Shares of Apple (AAPL -0.66%) were slammed today, with the stock falling as much as 9% at one point. That decline has moderated some, with the stock down 5% as of 12:50 p.m. EDT.

Much of the tech stock's decline was likely fueled by the market's overall sharp decline on Monday. But a report on low iPhone sales in China during February is probably weighing on shares as well.

Six iPhone 11 devices being splashed by water

iPhone 11. Image source: Apple.

So what

Apple sold fewer than 500,000 iPhones in China during February, according to data from the China Academy of Information and Communications Technology (CAICT). These shipments were down about 55% from February 2018.

It's no surprise, of course, to see that iPhone sales in China took a hit during February. Apple management warned investors on Feb. 17 that it no longer expected to hit its revenue guidance for its fiscal second quarter, citing constrained iPhone production and lower demand for its products in China due to the novel coronavirus outbreak in the country. 

Now what

Apple had said it expected the negative impact the coronavirus had on both production and demand to be temporary, noting in its Feb. 17 press release that its underlying business remained "fundamentally strong..."

Of course, the coronavirus outbreak has spread to other countries since then, and it's unclear how this will impact Apple's global sales.