As of this morning, Apple has officially lost its title as the world's most valuable publicly traded company, with shares falling below $400 for the first time in over 18 months. So what prompted today's steep drop? Cirrus Logic, an Apple analog and audio chip supplier, hinted late Tuesday at a disappointing revenue forecast in iPhone and iPad production, which in turn caused a minor panic among shareholders. This leaves Apple stock down more than 24% so far in 2013 and market capitalization below the $400 billion level.

An Apple spokesperson declined to comment on today's developments, though the company is set to report its quarterly results from January to March on Tuesday of next week. Stick around for updates.