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 Brunswick (NYSE:BC) were riding higher today, jumping as much 13% today after a strong earnings report.

So what: The boat-engine and sporting-goods maker said net income jumped 25%, as it beat earnings estimates by $0.13 with per-share profit of $0.76. Revenue was up only 3.7%, however, slightly below analyst consensus. Sales grew on higher demand for marine products and accessories, as well as for fitness equipment; however, a decline in fiberglass and bowling products counteracted the gain. A lower tax rate was the primary for the strong earnings growth.

Now what: Brunswick also upped its full-year EPS guidance to a range of $2.30 to $2.50, from a ranger of $2.20 to $2.45, on the strength of today's report, but that was primarily on the strength of the last quarter. Considering that a majority of the gains came from the lower tax rate, investors shouldn't expect to see a repeat performance next quarter. Shares ended the day up 5.9%, after a fast start, which seems to be an accurate of today's earnings beat. To get more on Brunswick, just add the company to your Watchlist here .

Fool contributor Jeremy Bowman and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.