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: InterDigital (Nasdaq: IDCC) dropped 23% in intraday trading today after news that Google (Nasdaq: GOOG) had agreed to acquire Motorola Mobility (NYSE: MMI) dampened hopes that Google might buy InterDigital.

So what: InterDigital has had three large pops in the past six weeks. It began with a 17% pop on July 1, as investors reassessed the value of InterDigital's patent portfolio based on strong bids for Nortel's patent portfolio. On July 19, the stock popped nearly 30% on news that InterDigital's board had initiated a "strategic review" that could result in a sale of the company. The following day it popped another 19% on news reports that Google was interested in bidding on InterDigital.

Now what: InterDigital's patent portfolio is rich in intellectual property in the hot wireless communications sector. Google bid on Nortel's patent portfolio but lost out to a consortium that paid $4.5 billion and included Apple, Microsoft, Research In Motion, Sony, EMC, and Ericsson. While Motorola Mobility's patents may lessen Google's interest in InterDigital, other consortium members -- along with InterDigital licensees such as Samsung Electronics, LG Electronics, and HTC -- are potential buyers of InterDigital.

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Fool contributor Cindy Johnson owns shares of InterDigital. 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.