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 AOL (NYSE: AOL) fell 16% in early trading and closed down more than 15% on heavy volume after CEO Tim Armstrong said he'd like his company to become the No. 3 provider of online display advertising. ComScore currently ranks AOL fourth behind Facebook, Yahoo! (Nasdaq: YHOO), and Microsoft (Nasdaq: MSFT).

So what: Investors weren't impressed, and rightfully so. Armstrong told the audience at a Goldman Sachs conference that although the goal "may not sound ambitious," it was a step up -- or, more precisely, "a unique place to occupy." And I thought only lobbyists were so brazen.

Now what:  Chalk it up to Armstrong being OK with underachievement -- or, at the very least, making too little from new properties TechCrunch and The Huffington Post. Do you agree? Would you buy at current levels? Please weigh in using the comments box below.

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Fool contributor Tim Beyers is a member of the Motley Fool Rule Breakers stock-picking team. He didn’t own shares in any of the companies mentioned in this article at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Google+ or Twitter, where he goes by @milehighfool. You can also get his insights delivered directly to your RSS reader.

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