The milestones are coming quickly for an ascending Sirius XM Radio (NASDAQ:SIRI).

I was toasting the satellite radio operator as an eight-bagger just last week, and it closed out the trading week at $0.50 a share -- a clean 10-bagger from the $0.05 a share at which it bottomed out back in February.

One can always argue that multiples are easy when you start with something as small as a nickel, but the undeniable message is that Sirius XM longs are steamrolling the shorts. That's been the case fairly consistently since the company got bailed out by Liberty Media Interactive (NASDAQ:LINTA) with a critical capital infusion.

Assurances of Sirius XM's near-term financial survival and a huge short interest have helped fuel the mother of all short squeezes. There were 181 million Sirius XM shares sold short as of the end of March. We will know the mid-April tally when Nasdaq disseminates the information on Friday.

Many of the shorts likely ran for cover, given the limitless downside of a short position when a stock is barreling higher.

Sirius isn't the only winner here. Shares of Liberty Media have more than doubled since last month's low of $2.42 a share. It was able to score Machiavellian terms in its $530 million debt deal with Sirius, scoring chunky yields and a fat 40% slice of Sirius XM. With every uptick at Sirius XM, Liberty Media becomes a bigger genius.

The savvy move in beating out EchoStar (NASDAQ:SATS) for its stake in Sirius XM is winning Liberty more than just hero worship. Shares of CBS (NYSE:CBS) took off on Friday, after Liberty CEO Greg Maffei made an off-the-cuff remark about buying the broadcasting giant.

The bigger question at this point is whether Sirius XM can keep the good times rolling. The Liberty deal was clearly dilutive, capping the stock's long-term upside, now that future operating profits must be divided among billions more shares of Sirius XM. However, the real overhang at Sirius XM -- the reason that shares were being swapped for pennies -- was that investors didn't think it could get through February without filing for Chapter 11 bankruptcy reorganization.

Clearly, Sirius made it. The company has some pesky debt hurdles to clear in 2010, and especially come 2011, but it has enough breathing room for the next few quarters. If its initiatives in backseat video, premium Web radio, and smartphone apps bear fruit, the near-term gains will be more than justified.     

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