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 online travel search company Kayak Software (NASDAQ: KYAK) soared a whopping 27% on Friday after industry giant priceline.com (NASDAQ:BKNG) offered to acquire it for $1.8 billion.

So what: The cash-and-stock deal values Kayak at $40 per share and represents a 29% premium to its closing price on Thursday. Priceline is making the move to boost its travel search capabilities -- Kayak lets customers compare prices of different travel sites at once -- and judging from its own stock's flat action today, Mr. Market thinks management is paying a relatively fair price to do it.

Now what: The deal is expected to close by late first quarter 2013 and should have a minimal impact on Priceline's non-GAAP EPS next year. "KAYAK has built a strong brand in online travel research and their track record of profitable growth is demonstrative of their popularity with consumers and value to advertisers," said Priceline CEO Jeffery Boyd. "We believe we can be helpful with KAYAK's plans to build a global online travel brand." So while Kayak shares are likely all popped out, Priceline's bolstered U.S. presence might drive some outsized gains going forward.

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