Apple's stock sank 5.6% in midday trading on Wednesday following a report from a key supplier that indicated sales could be slowing.
On Tuesday, Cirrus Logic, which supplies audio chips for iPhones and iPads, said sales of one of its chips was slipping. That led investors and some analysts to infer that Apple sales were also sliding, spooking shareholders one week before the company is scheduled to report earnings.
Apple's stock fell 5.6% or $23.89 to $402.35 just after 12:30 p.m. EDT. Apple stock has not closed below $400 since late 2011.
Apple is scheduled to report second quarter earnings on April 23.