Shares of Green Mountain Coffee Roasters (Nasdaq: GMCR) are down this week, while frenemy Starbucks (Nasdaq: SBUX) is trading higher, after the latter began selling a single-cup beverage brewer this week. While the two companies have played nicely in the past, and have suggested they will going forward, as well, this move ups the ante a bit. 

At the end of the day, the team wants one question answered: How much of Green Mountain's market share can Starbucks take?

With Green Mountain as cheap as it's ever been, many investors are wondering whether this is the end of the former market darling, or the perfect entry point for an enormous rebound. You can find our recommendation for how to play the company in our new premium research report. In it, you'll find everything you need to know about Green Mountain, including whether it's a buy at today's prices. Click here for instant access. 

Chris Hill owns shares of Starbucks. James Early has no positions in the stocks mentioned above. Joe Magyer has no positions in the stocks mentioned above. Ron Gross has no positions in the stocks mentioned above. The Motley Fool owns shares of Starbucks and has the following options: long DEC 2012 $16.00 puts on Green Mountain Coffee Roasters, short DEC 2012 $21.00 calls on Green Mountain Coffee Roasters, and short JAN 2013 $47.00 puts on Starbucks. Motley Fool newsletter services recommend Green Mountain Coffee Roasters, Starbucks, and Williams-Sonoma. 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.