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 Leap Wireless International (Nasdaq: LEAP) lived up to their name today, having jumped as high as 15% on extremely heavy trading volume.

So what: In the just-reported first quarter, Leap added a lot more wireless subscribers to its Cricket service than anticipated. That led to massive sales but also very high operating costs as one-time costs for those new accounts had to be accounted for. Investors are clearly happy with that trade-off.

Now what: The report also inspired a glowing review from analyst firm Collins Stewart, which raised its target price for the stock to $22 per share and drew favorable comparisons with pay-as-you-go rival MetroPCS (NYSE: PCS). Collins Stewart loves the wireless industry in general, posting five CAPS ratings in the sector with nary a thumbs-down vote among them -- and a flip-a-coin accuracy of 50%. Take that upgrade with a pinch of salt, but rest assured that adding customers very quickly is good for subscription services like Leap in the long run.

Interested in more info on Leap Wireless International? Add it to your watchlist.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. 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 is investors writing for investors.