Buzz surrounds takeover of 2009's best performing stock

There's an interesting merger percolating in the coffee world. Peet's Coffee & Tea (PEET), the chain said to have been the inspiration for Starbucks (SBUX), said Monday it had reached a $213 million deal to buy Diedrich Coffee (DDRX), a big seller of java in single-serving cups for home brewing.

So what's the big deal? After all, small companies buy each other for a few hundred million dollars all the time. But Diedrich is probably the best-performing stock in the United States this year. In fact, it was up a mind-boggling 5,555.56 percent this year before the takeover by Peet's was announced. As recently as late March, it was trading for 42 cents; Peet's agreed to pay $26 a share to take it over.