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 social reviewer Yelp (YELP 0.60%) soared this morning by 15% after the company announced an acquisition and preliminary earnings. The company has since given up some of those gains.

So what: Revenue should be about $36.4 million, with adjusted EBITDA of $2.2 million. Both figures top the guidance that the company previously provided in August. Yelp's net loss for the quarter should be $2 million. Full financial results will be released on Nov. 1, at which time the company will also provide additional forward-looking guidance.

Now what: Yelp also announced that it has acquired Qype, the largest local-review site in Europe, to help spur the company's international expansion. Qype currently has about 2 million reviews on its site and sees 15 million unique visitors monthly across 13 different countries. The total purchase price was roughly $50 million and was comprised of cash and 970,000 shares of stock.

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