Have you been swept up in bitcoin mania? Bitcoins purchased at the beginning of this year were valued at $13.50. As of Dec. 9, they were trading at close to $900. That’s a rise of more than 6000 percent! Many folks are eyeing the virtual currency as an easy way to make huge profits. But KPLU financial commentator Greg Heberlein urges caution. Bitcoin prices may very well continue their march into the stratosphere. Or the bubble could burst.