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 Goodyear Tire & Rubber (NASDAQ:GT) were zooming ahead today, gaining as much as 15% after second-quarter profits surged higher.

So what: Adjusted earnings per share for the tire maker more than doubled to $0.76 in the quarter from $0.33 a year ago, soaring past estimates of $0.48. Revenue actually fell 5% to $4.89 billion, but that still edged out estimates of $4.88 billion. Latin America sales were particularly strong, improving 6% as operating income in the region jumped 42%. Goodyear also overcame a 10% drop in North American revenue by focusing on higher-end tire sales, and said full-year operating income should be at the top end of its previously stated range of $1.4 billion to $1.5 billion.

Now what: The drop in revenue may be discouraging, but improving auto sales should help Goodyear's revenue stabilize. CEO Richard Kramer was optimistic about the current quarter, saying he expects a 3% to 5% volume increase on "continued improvement in emerging markets and slow but steady recovery in mature markets."  With the stock's 2013 P/E under 9, there should be plenty of upside potential if management can keep its promises. I'd expect shares to move higher.

Fool contributor Jeremy Bowman has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not 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.