Popular cryptocurrencies such as Bitcoin and Ethereum are built on blockchain technology. Blockchains like Bitcoin and Ethereum are constantly growing as new blocks are added to the chain, increasing the security of the ledger dramatically. Mr. Powell has argued that Bitcoin is more like gold than the dollar. It has value because it’s rare and people want to hold it, so it can even at times be traded for other goods and services, but it is not government-guaranteed money. This PwC index…