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: Expedia (Nasdaq: EXPE) popped 15% in intraday trading today after announcing plans to split the company in two.

So what: The company plans to either spin TripAdvisor, which accounts for approximately 11% of revenue, off to shareholders or reclassify Expedia's stock. If shareholders approve a spin-off, Expedia expects to complete it during the third quarter.

Now what: Expedia's P/E ratio of 13.3 times is less than half the travel and tourism industry's 32.5 times, and management is likely frustrated by the low valuation. TripAdvisor's growth rates and margins are much more attractive than the rest of the company's. Investors would likely pay more for TripAdvisor on its own, so separating it could increase the combined market value.

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