Source: Sirius XM.

Naysayers are clearing out of satellite radio. There were 163.5 million shares of Sirius XM Holdings (NASDAQ:SIRI) sold short at the end of last month. That may seem like a big number, but for a low-priced and actively traded stock like Sirius XM it's actually pretty low.

That's the fewest number of SiriusXM shares sold short in more than a year. It's also a far cry from the previous tally of 247.3 million bearish bets in play just two weeks earlier. 

Normally this kind of sharp drop in short interest would be attributed to a short squeeze, but it's hard to make that argument here. There weren't any substantial positive developments taking place during the latter half of last month that would send the bears packing. The stock itself didn't exactly set the world on fire, though going from $3.53-$3.63 in that two-week stretch was double the S&P 500's return.

What's going on here? I have a theory, and it's that the one thing shooing away the non-believers is boredom. Sirius XM had been one of the most volatile stocks over the years, a blazing 70-bagger since bottoming out at a nickel five years ago. It's been pretty tame this year, trading in a surprisingly tight range given the previous years of wild price swings. Sirius XM's one-year beta clocks in at a tame 0.84, a far cry from its five-year beta score of 1.47.

For better or worse, Sirius XM is getting pretty predictable. Analysts have nailed Sirius XM's earnings with their profit targets in each of this year's first three quarters. Revenue growth is also decelerating at a pretty steady pace. The media giant's guidance calls for revenue of $4.15 billion this year, up 9% after climbing 12% last year and 13% the year before that. Wall Street's eyeing 8% top-line growth next year.

Potential buyout volatility also came and went when investors balked at Liberty Media's (NASDAQ:FWONA) intentions to swallow it whole. If a majority stakeholder -- and that's just what Liberty Media was and continues to be -- couldn't take over the satrad monopoly it's highly unlikely that the handful of companies that could afford Sirius XM would fare any better. That may seem to limit the situational upside, but it also keeps the downside of disappointment in check.

Armed with 26.7 million total subscribers, Sirius XM isn't going anywhere. Sirius XM is targeting $1.425 billion in adjusted EBITDA and $1.2 billion in free cash flow for all of 2014, and that also makes an investment less speculative. Slowing growth isn't bullish, but predictable liquidity and a steady trickle of net new subs given the buoyant car market also eat away at any of the bearish tendencies that naysayers were counting on to drive the stock lower

Sirius XM is boring, and that's not not necessarily a bad thing. The bears followed volatility out the door, and swapping the potential of a short squeeze for stability isn't the worst thing that could happen for Sirius XM investors.  

Rick Munarriz has no position in any stocks mentioned. The Motley Fool owns shares of Sirius XM Radio. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.