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 Zagg (Nasdaq: ZAGG) -- protector of electronics products -- shot up as much as 21% in intraday trading today following a 24% slide yesterday.

So what: Zagg shareholders were absolutely cursing Apple's (Nasdaq: AAPL) Steve Jobs yesterday as that smooth-talking so-and-so presented the iPad 2 and -- more notably for those with a stake in Zagg -- the iPad Smart Cover, a slick, magnetic cover-cum-stand for the iPad and a direct competitor to Zagg's ZAGGmate case (recently touted by none other than MC Hammer on The Oprah Winfrey Show). Today, though, it appears investors have taken time to think about the situation and have realized the real Zagg breadwinner -- invisibleSHIELD -- is still going to be a must-have for many iPad 2 buyers.

Now what: Zagg's products are good for a wide range of products, but let's be honest, the company's meteoric rise over the past few years has been largely thanks to the i-product empire. While the introduction of the Smart Cover may not be a huge blow to Zagg, it should make investors stop to think about the potential for the shark to leave behind fewer scraps for the remora.

Want to keep up to date on Zagg? Add it to your watchlist.

                                                           

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Fool contributor Matt Koppenheffer does not own shares of any of the companies mentioned. You can check out what Matt is keeping an eye on by visiting his CAPS portfolio, or you can follow Matt on Twitter @KoppTheFool or on his RSS feed. The Fool's disclosure policy prefers dividends over a sharp stick in the eye.