Krugman: "Unlike pieces of paper with dead presidents on them, those are anchored by the fact that you can use them to pay taxes. There's no anchor for bitcoin."
Possible explanation for the rapid rise in price? Over 200 million people in Africa.
According to multiple reports online Mavrodi is running a giant ponzi scheme in Africa and several other lesser developed countries where participants are told they can make "30% to 50% returns monthly" and is based on bitcoin. Most are low income areas, and the participants have little trust in banks and financial institutions in those countries according to reports. They claim to have over 200 million participants involved in his latest ponzi scheme, mostly in Africa.
See reports online published in September, October, and November 2017 for: