It is called a "crash". Similar to the dot come "crash" which took about 2 years. Crashes don't happen in one day like people think, it takes place over the course of months with ups and downs, but a steady downward trend.
BitCoin is crashing. Sorry, $238 to $77 over the course of 2-3 months is a classic crash, and it is continuing.
Well this guy just traded those shiny coins in for some LTC. At least there it's been a bit more steady and in fact shows signs of improving.