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 VirnetX Holding (AMEX: VHC) surged close to 18% today on what appears to be increasing speculation that Apple (Nasdaq: AAPL), Google (Nasdaq: GOOG), or another entity will bid for its patents related to 4G technology.

So what: We've seen this sort of behavior before. This time, speculative articles at Seeking Alpha and elsewhere suggest a bid isn't far off. How big a bid is unknown at this point, but considering that Google was willing to pay what amounted to an $8 billion premium for Motorola Mobility's (NYSE: MMI) intellectual property, bulls are expecting a significant offer.

Now what: Fools should nevertheless be careful. Thanks to bullish speculators, the stock has more than tripled over the past year and is up more than 40% year-to-date. As such, much of the premium they expect could already be cooked into the price. Do you agree? Would you buy at these levels? Weigh in using the comments box below.

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