Just because of Covid-19 aka Corona Virus.
Your are right but, the deep created by cryptocurrency cannot be compared to others like gold and metals from the general market. We have seen before SARS among others pandemic but never affected the cryptocurrency, gold and metals as we have seen few days ago. This made me believe that, there's more to this drastic and dynamic fall from cryptocurrency.
In my.opinion, panicked investors were responsible for the outbreak of the crash which lead to total downturn of the entire markets. The panic sales make this deep on cryptocurrency because of it volatility among other things. I "strongly believe in the effect of panic sales"