M3 (which includes all the other buckets) minus M1 is worth about 45 trillion US dollars. We will include this as a store of value that is comparable to bitcoin. To this, we will also add an estimate for the worldwide value of gold held as a store of value. While some may use jewelry as a store of value, for our model we will only consider gold bullion. The US Geological Survey estimated that at the end of 1999, there were about 122,000 metric tons of available above-ground gold. Of this, 48%, or 58,560 metric tons, was in the form of private and official bullion stocks. At an estimated current price of $1200 per troy ounce, that amount of gold is today worth upwards of 2.1 trillion US dollars. Since there has recently been a deficit in the supply of silver and governments have been selling significant amounts of their silver bullion, we reason that most silver is being used in industry and not as a store of value, and will not include silver in our model. Neither will we treat other precious metals or gemstones. In aggregate, our estimate for the global value of stores of value comparable to bitcoin, including savings accounts, small and large time deposits, money market funds, and gold bullion, come to 47.1 trillion US dollars.
More recently, at a congressional hearing on Capitol Hill, global economist and New York University professor Nouriel Roubini said, "Crypto is the mother or father of all scams and bubbles." He called out "swindlers" who tapped into investors' fear of missing out and took them for a ride with "crappy assets that went into a bust and crash — in a matter of months — like you have not seen in any history of financial bubbles."