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 Chinese online gaming specialist Perfect World (Nasdaq: PWRD) plunged 18% Thursday after the company lowered its current-quarter outlook.

So what: Perfect World has been crushed over the past several months on concerns over the lifecycle of its games, and today's downside guidance -- management now expects third-quarter revenue of $109.8 million versus its previous forecast of $118.3 million -- only reinforces those fears. In fact, the shares are hitting a new 52-week low on the news and are down 45% over the past year.

Now what: I'd look into this pullback as a possible buying opportunity. While the lowered sales guidance is disappointing, it still represents year-over-year growth of 21% to 28% for its core online business. With the shares trading at a clear P/E discount to rivals like NetEase (Nasdaq: NTES) and Shanda (Nasdaq: SNDA), Perfect World already seems heavily priced for imperfection.

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