There's a comfortable calm in shares of Sirius XM Radio (Nasdaq: SIRI) these days.

The sheer volume is still there, with more than 100 million shares of the company exchanging hands in each of the past few trading days. However, the stock has closed between $0.83 and $0.95 a share through March. That may be a significant range on a percentage basis, but it's a sea of tranquility relative to Sirius XM's typical volatility.

There's nothing wrong with relative boredom. In fact, it's one of the many reasons to warm up to Sirius XM these days. Let's go over a few of the reasons to be cautiously bullish at this point.

1. Speculators are being shaken out
Sirius XM shares closed at $0.67 on Jan.19. Things began to heat up the following morning, when the satellite-radio giant announced that it had landed 257,000 net new subscribers during the fourth quarter along with a rosier cash flow outlook. Less than a month later, the stock traded as high as $1.18 a share.

The fact that the stock has shed roughly half of those heady gains may be disconcerting to momentum investors. Chartists may not necessarily be technically impressed. However, I'm happy to see a lull in the mania. The mad rush to trade above the $1 mark for 10 consecutive trading days to avoid exchange delisting added unnecessary drama and heightened expectations to the mix. Sirius XM fell two days short of the goal, and now it seems as if the speculative cleansing is complete.

2. Auto sales are back
It's no surprise to find Sirius XM shedding subscribers during the first two quarters of 2009 -- when the auto market was at its bleakest -- before bouncing back as auto sales revved up in the latter half of the year.

Shares of Ford (NYSE: F) have popped nearly 14-fold since bottoming out at $1.01 just 16 months ago. The Mustang sallying finds Ford sales soaring 43% in February over the same month a year earlier (and an equally impressive 22% sequential jump for a hot January).

New cars mean fresh factory-installed Sirius or XM receivers in a growing number of models. Since 46% of those drivers are converting into paying subscribers after their free trials run out, the assembly line is the lifeblood of satellite radio.

3. The reverse split myth is being debunked
Financial (Nasdaq: ETFC) became the latest company to resort to a reverse split to rescue its low share price. It's a zero-sum move, but it's not a fatal tactic. AIG (NYSE: AIG) and Coeur d'Alene Mines (NYSE: CDE) are trading higher than when they executed reverse splits last year.

Sirius XM shareholders have already approved the split, but CEO Mel Karmazin is hesitant to pull the trigger. He'll make the move if Nasdaq OMX Group (Nasdaq: NDAQ) forces the split as a way for the shares to regain listing compliance, but this shouldn't be about which side of the decimal Sirius XM is trading at in a few months.

E*TRADE, AIG, and Coeur d'Alene all were trading above the $1 mark when they announced their intentions. There are institutional investors -- and even a few naive individual investors -- who judge a stock by its share price and are reluctant to go after shares with pocket-change prices.

It's not fair. Sirius XM has 3.9 billion shares outstanding, and that figure is bumped to 6.5 billion when one considers Liberty Capital's (Nasdaq: LCAPA) 40% preferred share stake. Even if Sirius XM is able to pare down its roughly $3 billion in debt, its buoyant share count will keep the per-share price in check unless it finds a way to radically ramp up its revenue or dramatically increases its margins. I'm bullish on Sirius XM, but a realistic valuation won't hit on the $3 to $5 share price that will be taken seriously by institutions for some time.

Why wait? Reverse splits have a dirty connotation because they often come from desperate companies that are in the process of fading. Now that Sirius XM has had a successful year of debunking the cynics, a reverse split can only widen the appeal of ownership.

4. The fundamentals are better than you think
Sirius XM's outlook is certainly brighter than it was a year ago. Subscriber growth is back, and the satrad star is looking to close out 2010 with 500,000 more accounts than it started. Sirius XM also sees adjusted operating profits of $550 million, 20% ahead of last year's surprisingly strong showing.

Instead of worrisome headlines, when news breaks on Sirius XM it is usually positive. Credit rating upgrades, debt refinancing at more attractive rates, and new content deals are par for the course. In other words, this isn't the minefield it was during the worst of the recession.

Put it all together and Sirius XM is in a much better place than skeptics think, despite its admittedly hefty enterprise value.

I welcome the lull, because the improving fundamentals suggest that when the silence is broken it should be to the upside.

Will Nasdaq delist Sirius XM if it isn't in compliance after the appeal process? Share your thoughts in the comments box below.

Nasdaq OMX Group is a Motley Fool Inside Value selection. Ford Motor is a Motley Fool Stock Advisor pick. Motley Fool Options has recommended a write covered calls position on Nasdaq OMX Group. Try any of our Foolish newsletters today, free for 30 days.

Longtime Fool contributor Rick Munarriz is a subscriber to both Sirius and XM. He does not own shares in any of the stocks in this article. He is also a member of the Rule Breakers analytical team, seeking out the next great growth stock early in its defiance. The Fool has a disclosure policy.