Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of OmniVision Technologies (Nasdaq: OVTI), which supplies illumination products for smartphones, crashed a staggering 30% on Friday after its second-quarter forecast came in well below Wall Street expectations.

So what: OmniVision's current-quarter revenue outlook missed estimates so badly -- $255 million to $275 million versus the analyst consensus of $306 million -- that investors can't help but assume a big market share loss on the smartphone side. The stock has been under pressure in recent months on fears that Apple (Nasdaq: AAPL) would instead go with Sony (NYSE: SNE) as its image sensor supplier for the next iPhone, and management's dismal forecast only adds validity to those concerns.

Now what: Expect the pain to continue in the short term. Some Wall Street analysts estimate that OmniVision has likely already lost half of its business from Apple, so don't expect the stock to see an earnings growth-fueled bounce anytime soon. Of course, with the shares now down more than 50% over the past three months alone, OmniVision could be a long-term opportunity worth looking into.

Interested in more info on OmniVision? Add it to your watchlist.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.