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 low-cost wireless provider Leap Wireless International (Nasdaq: LEAP) ran out of minutes today, and the stock plummeted 32% as a result.

So what: Earlier this week, Leap fell because competitor MetroPCS (NYSE: PCS) reported weak earnings. But this time, it's Leap's own fault. The company reported a loss of $0.85 per share, exploding from only a $0.24-per-share loss last year. Broadband customers left in droves.

Now what: There isn't a lot of good news today for Leap investors. The company is trying to attract more profitable smartphone customers, but the transition isn't going quickly. Analysts aren't even expecting a profitable year in 2012. I wouldn't venture anywhere near the buy button on Leap Wireless' shares today.

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