It's been a good time to be long Sirius XM Radio (Nasdaq: SIRI), and a dangerous time to bet against the satellite radio giant.

Shares of Sirius XM hit a fresh two-year high this morning, and that's with the uncertainty surrounding Howard Stern's contract, which expires in two months.

After four profitable quarters and what has already been confirmed as five quarters of net subscriber growth, Sirius XM isn't the crapshoot wager it was when speculators were wondering if EchoStar (Nasdaq: SATS) or Liberty Capital (Nasdaq: LCAPA) would save it from the jaws of bankruptcy.

No one is picking Sirius XM in corporate death pools these days. Institutional investors are even starting to buy in, regardless of the stock's pocket-change pricing.

What about Stern, though?

CEO Mel Karmazin expected an announcement before the company's third-quarter conference call, which is taking place next Thursday morning.

Both sides are negotiating in public. Stern has entertained the possibility of launching his show as a streaming app, something that is no longer a laughably bad decision. Apple (Nasdaq: AAPL) has moved more than 100 million iPad, iPod touch, and iPhone devices that run on the App Store-centric iOS platform. Rival smartphone makers have their own nascent marketplaces.

The rub with that strategy is that folks will expect more Stern if he sets himself up as a stand-alone premium product. He has often indicated that he wants to scale back on his number of live broadcasts, and that's something that's easier to do as one of the many premium channels on Sirius.

We'll see how it all plays out. Stern is wrapping up a five-year deal that was originally valued at $500 million, so it's not as if his leaving would be catastrophic. Sirius XM would be able to dramatically shave programming overhead. The real question will be how many subscribers would follow Stern out the door.

In the meantime, next Thursday will be telling. We've been here before. Sirius XM pre-announces great subscriber numbers. The stock runs up ahead of the report. Shares sell off on the actual quarterly earnings release, despite the solid improvement.

It could be different this time, given the pending programming news, or history could simply repeat itself. Healthier institutional stakes and greater model viability can only help, but the arrival of more analytically minded investors will force the stock to tackle its valuation demons.

Sirius XM is never boring, but the next few days will be especially interesting.

So how high can Sirius XM go? Share your thoughts in the comments box below.

Apple is a Motley Fool Stock Advisor pick. The Fool owns shares of Apple. 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.

Longtime Fool contributor Rick Munarriz is a subscriber to both Sirius and XM. He does not own shares in any of the companies in this story. 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.