Shares of OmniVision Technologies (UNKNOWN:OVTI.DL) dropped as much as 10% in today's trading after the company announced earnings yesterday after the bell. The second-quarter numbers came in above analysts' expectations, but according to tech and telecom bureau chief Evan Niu, the key problem was lowered guidance for the third quarter. Headwinds in the smartphone market were partly to blame for the guidance, as 60% of OmniVision's sales come from the mobile phone market. Between slower sales and heavy competition from Sony and Samsung, Evan thinks that OmniVision will have a lot of trouble going forward, and he doesn't think it's a good investment right now.

Evan Niu, CFA, has no position in any stocks mentioned. Mark Reeth has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.