They say that age is just a number, but the same can be said about a stock price. Many of the market's big winners began as low-priced stocks. The market is full of investments with single-digit price tags, and the low prices are typically warranted. Sometimes, however, it's just a stock that's temporarily out of favor, or just hasn't been unearthed by mainstream investors.

Low-priced stocks are risky, but the upside is potent when you aim just right. Let's go over Sirius XM Radio (SIRI 1.60%)Pandora (P), and Glu Mobile (GLUU), three names that could be among the top stocks trading under $10 a share.

Patrick Stewart and Hugh Jackman at a Sirius XM Town Hall interview.

Image source: Sirius XM Radio.

Sirius XM Radio

The market often associates low-priced stocks with a lack of profitability or consistent growth, but Sirius XM rocks on both fronts. It's posted positive earnings for 23 consecutive quarters, and revenue has risen every single year. 

Sirius XM's stock price is low as a result of a painful recapitalization, the merger with XM, and a solvency-preserving bailout that bloated its share count. Since bottoming out at a $0.05 in early 2009, Sirius XM has been one of the market's biggest winners.

There are now a record 32 million subscribers to the satellite-radio service, and Sirius XM is a cash machine cranking out $1.5 billion in free cash flow this year. Sirius XM even pays out a modest quarterly dividend. The price may be low, but Sirius XM is not like any penny stock you may know.

Pandora Media

The pioneer of digital music streaming has fallen on hard times. User growth has stalled, and it's struggling to complete in the cutthroat on-demand niche. Pandora is a distant third among online music services when it comes to premium subscribers. It lowered its full-year revenue guidance in its most recent quarter.  

Pandora is in the market's doghouse, but it won't always stay that way. There are still 76 million active listeners, and even if they're mostly freeloaders, Pandora is getting better about monetizing that traffic. Sirius XM has also taken a minority stake in Pandora, something that may put a damper on near-term takeover speculation, but should open up new opportunities for both companies. Pandora's down, but it's not out. 

Glu Mobile

Mobile-gaming companies live and die by hit titles. Glu Mobile was a big winner three years ago when Kim Kardashian: Hollywood raced up the app charts, opening the door for other young celebrities to team up with Glu for similar fame-chasing simulators. It's now riding high on the back of Design Home, a home-designing game that finds Glu dramatically juicing up its prospects.

Glu Mobile was forecasting just $215 million to $225 million gross bookings back in February. That goal post was moved to between $270 million and $280 million in May, rising to between $307 million and $312 million earlier this month

Nothing boosts a stock like rapidly improving prospects, and Glu Mobile stock has soared 80% this year. Gamers are fickle, but Glu diversifying its product line seems to be helping.