I’m not sure where the expression ‘cryptocurrency’ came from, but Bitcoin is the polar opposite of a cryptocurrency.
Anybody using bitcoin is allowed to download and examine the books on how much bitcoin actually exists.
As such, the only cryptocurrencies I can think of are the US Dollar, the Yuan, and other fiat currencies.
Oh, and HSBC has now restricted ‘large’ withdrawals (greater than 3,000 Yuan).
Bitcoin is a mortal threat to fiat currencies, in that every bitcoin user knows to the last bitcoin how much bitcoin is out there. The fluctuations you seen in bitcoin value ISN’T fluctuations in bitcoin, its fluctuations in the currencies being compared to it.
The only way to stop bitcoin is to hit the kill switch - take out the internet. Do that, and bitcoin is worthless, until the net is restored.