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 pleasure boater Brunswick (NYSE: BC) popped nearly 11% in late trading Thursday. It sounds like a lot, but what made it pop was an even bigger number -- Brunswick's second-quarter profit was $0.75 per share, a six-fold increase over last year's Q2.

So what: That's just the start of the good news. According to management, Brunswick is set to report full-year profits that could also be as high as $0.75. Worst-case, Brunswick thinks it might earn as little as $0.60 this current quarter, but even that would be nearly half-again the consensus forecast on Wall Street ($0.43).

Now what: Are you excited yet? Don't be, because any good news Brunswick reports is already priced into the stock -- and then some. Consider the best-case scenario. Say Brunswick earns $0.75 this year. At a $22 share price, you'd be paying 29 times current-year earnings for those shares, quite a high price for a company that's only expected to grow 13% per year over the next five years.

Even if Brunswick achieves the near-tripled profit that Wall Street has it earning next year ($1.19 per share), you're still looking at a forward P/E of 18.5. At these price levels, Brunswick is anything but a safe port in the storm. My advice: Seek your profits elsewhere. There are plenty more boats in the sea, and cheaper ones to boot.

Not ready to abandon ship just yet? That's fine. But at least add Brunswick to your watchlist and keep a sharp lookout for shoals.

Fool contributor Rich Smith does not own (or short) shares of Brunswick. The Motley Fool has a disclosure policy.

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