![Planet Money show](https://d3dthqtvwic6y7.cloudfront.net/podcast-covers/000/026/080/small/npr-planet-money.jpg)
Summary: Since the start of the year, the Japanese yen has risen by about 12 percent against the dollar. The euro has fallen by about 1 percent. Then there's bitcoin, a virtual currency that doesn't even exist in the physical world. In the past few months, the value of bitcoin has risen by more than 1,000 percent — from less than $20 per bitcoin a few months ago to more than $200 today. On today's show, we ask: Is a skyrocketing value a good thing or a bad thing for bitcoin?