there is no $16B-$20B dollars!
thats the speculative bubble number based on a few thousand coins being stired around in exchanges to have a $1000 'price' and the multiplying it by 16m
there are not 16-20 billion actual dollars sitting in bank accounts.
i can make an altcoin tomorrow with 5,000,000,000,000 premined coins. get just 1 coin onto an exchange and sell it to myself for $1.. and instantly have a $5trillion market cap.
so stop talking about the speculative bubble number.. its meaningless. all the holders of the 16m coins of bitcoin are not promised or guaranteed $1000 if they all cashed out today. its not a 'valuation' .. its a bubble number of multiplication