Bitcoin is undergoing a flashcrash or temporary shutdown in pricing. This has to do with the fact that the FBI is selling of 30.000 bitcoins that were confiscated from a black market end of last year. The market is currently expecting the price to drop... And hence it is dropping. Another factor was the threat of the 51percent network takeover, but this has been resolved by the respective vendor by removing hashing power from the bitcoin mining effort. This has somewhat assured the market as of late.
Bitcoin crash ongoing