I follow quite a lot of companies, so the usefulness of a watchlist to me cannot be overstated. Without my watchlist, I'd be unable to keep up on my favorite sectors and see what's really moving the market. Even worse, I'd be lost when the time came to choose which stock I'm buying or shorting next.

Today is Watchlist Wednesday, so I'm discussing three companies that have crossed my radar in the past week -- and at what point I may consider taking action on these calls with my own money. Keep in mind that these aren't concrete buy or sell recommendations, nor do I guarantee I'll take action on the companies being discussed weekly. What I can promise is that you can follow my real-life transactions through my profile and that I, like everyone else here at The Motley Fool, will continue to hold the integrity of our disclosure policy in the highest regard.

Sirius XM (NASDAQ:SIRI)
Sirius XM is making waves today following the announcement after the bell yesterday that its CEO, Mel Karmazin, will be stepping down when his current contract expires on Feb. 1, 2013. The stock fell on the uncertainty of new leadership taking Sirius' helm, as Karmazin has been CEO of Sirius since 2004. However, I feel this is exactly the move teh company needs to move higher.

The only thing that's held me back from finally liking Sirius had to do with its poor management under Karmazin. As he was known for his notoriously large pay packages and pitiful stock performance, which saw Liberty Media (NASDAQ:STRZA) infuse Sirius with cash and take a sizable stake in the company, Karmazin's exit should allow for better transparency  --which, in turn, should open it to potentially more lucrative content deals. Sirius still has plenty of challenges ahead, including paying down about $2 billion in net debt, but with Karmazin out of the picture, I'd consider the satellite provider well worth the risk.

North American Palladium (NYSEMKT:PAL)
No matter how you cut it, palladium never seems to command the respect or value that gold or platinum do, yet there are just as many valuable uses for the rare metal. When platinum prices rise, palladium producers step in and supply the cheaper alternative used in catalytic converters to the automobile industry. In addition, it's a great alloy substitute in jewelry that keeps prices down for consumers.

Other than physically buying palladium itself, one way to play this precious metal is by purchasing North American Palladium -- one of the few pure-play palladium companies. Simply put, when palladium prices are up, North American Palladium's prospects are likely to rise -- assuming it's not having production issues, of course. Currently losing money and looking at a forward P/E of 27, it may not appear to be a particularly attractive value now. But, considering palladium's multiple uses, its rarity, and the premium price per ounce of platinum, I'm a long-term bull on this metal appreciating in value, which should translate into eventual profits for North American Palladium. I've said it before, and I'll say it again: It's definitely a company worth keeping an eye on.

Orexigen Therapeutics (NASDAQ:OREX)
Orexigen has performed well ever since VIVUS and Arena Pharmaceuticals (NASDAQ:ARNA) gained FDA approval for their respective anti-obesity drugs. News this week also suggests that the FDA would be willing to fast-track Orexigen's anti-obesity drug, Contrave, assuming it passes its Light Study, which measures major adverse cardiac events of Contrave versus the placebo in 9,000 patients, with flying colors.

As for me, I'm not sold on Orexigen yet. Last month the company filed a $150 million mixed security offering meant to raise cash, but which could also wind up diluting shareholder value. Its lead drug, Contrave, is still probably two years away from finding its way to pharmacy shelves even if it receives fast-track designation and sails through clinical trials. There's also that little bit about Arena's Belviq and VIVUS' Qsymia beating it to market by two full years. With Qsymia's failure to gain European Medicines Agency approval, the door has been swung wide open for Belviq to storm the international and domestic markets beginning in 2013. Contrave's pie is already shrinking and it's still quite a ways away from a potential approval. In short, I don't have to look far for reasons to be pessimistic about Orexigen.

Foolish roundup
Is my bullishness or bearishness misplaced? Share your thoughts in the comments section below and consider following my cue by using these links to add these companies to your free, personalized watchlist to keep up on the latest news on each company:

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. He's a total nerd when it comes to making lists. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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