Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Outerwall (NASDAQ:OUTR) climbed as high as 12% this morning after activist investor Jana Partners disclosed a 14% stake in the Redbox owner.

So what: Outerwall has posted lackluster results over the past few quarters, but Jana's stake serves as a powerful catalyst for an increase in shareholder value. In fact, Jana said that it plans on discussing several strategic options with management, including cost-cutting initiatives and even a possible sale of the company, prompting investors to bid up the stock in anticipation of some big moves.

Now what: Jana is now Outerwall's biggest shareholder, with 3.78 million shares. "Outerwall welcomes the opinions of its shareholders and is always open to constructive input," Outerwall said in a statement. "We are committed to driving value for all Outerwall shareholders and will continue to take actions to achieve this important objective." So while Outerwall shares might be too hot to touch right now, they're certainly worth watching for any pullbacks given all the room management has to cut costs and sell its mature or underperforming segments.

Fool contributor Brian Pacampara has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. 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.