Basically, cryptocurrencies are entries about token in decentralized consensus-databases. They are called CRYPTOcurrencies because the consensus-keeping process is secured by strong cryptography. Cryptocurrencies are built on cryptography. They are not secured by people or by trust, but by math. It is more probable that an asteroid falls on your house than that a bitcoin address is compromised.
From the outset, money market funds fell under the jurisdiction of the SEC as they appeared to be more like investments (most similar to traditional stocks and bonds) vs. deposits and loans (cash and cash equivalents the domain of the bankers). Although money market funds are quite close to and are often accounted for as cash equivalents their main regulator, the SEC, has zero mandate to control the supply of money, limit the overall extension of credit, mitigate against boom and bust cycles, etc. The SEC’s focus remains on adequate disclosure of risk, and honesty and integrity in financial reporting and trading markets. After adequate disclosure, the SEC adopts a hands off, let the buyer beware attitude. This is a bank run in the sense that there is a mismatch in maturities, and thus a money fund is a "virtual bank": the assets of money funds, while short term, nonetheless typically have maturities of several months, while investors can request redemption at any time, without waiting for obligations to come due. Thus if there is a sudden demand for redemptions, the assets may be liquidated in a fire sale, depressing their sale price.
Monero is the most prominent example of the CryptoNight algorithm. This algorithm was invented to add the privacy features Bitcoin is missing. If you use Bitcoin, every transaction is documented in the blockchain and the trail of transactions can be followed. With the introduction of a concept called ring-signatures, the CryptoNight algorithm was able to cut through that trail.
While the country was once home to the world’s most active cryptocurrency exchanges, authorities banned the venues last year and have since moved to block access to platforms that offer exchange-like services. — Fortune, "China Is Said to be Cracking Down on a Cryptocurrency Loophole," 28 Feb. 2018 Bitcoin, however, has become the cryptocurrency standard operating much like U.S. dollar would operate in public currency markets, but in the crypto realm. — Michael C. Dealoia, cleveland.com, "Cleveland-area entrepreneurs are pouring resources into new-currency technolgoy: Tech Czar Talk," 25 Feb. 2018 Some companies, such as KODAK, have promoted cryptocurrency investments in hopes of reviving their flagging businesses. — Mike Rogoway, OregonLive.com, "SEC suspends trading in companies run by former Oregon football star over cryptocurrency 'concerns'," 16 Feb. 2018
Looking closer we see that if you can meet the $3,000 minimum investment size, Vanguard’s VMMXX offers an appealing combination of relatively high returns with low expenses. If you don’t have a large amount of cash to invest, you should note that both FMPXX and FIDXX have $1MM investment minimums. If you have less than $1,000, SPRXX doesn’t meet the yield and expense ratio thresholds we laid out, but it doesn’t have an investment minimum. Looking closer we see that if you can meet the $3,000 minimum investment size, Vanguard’s VMMXX offers an appealing combination of relatively high returns with low expenses. If you don’t have a large amount of cash to invest, you should note that both FMPXX and FIDXX have $1MM investment minimums. If you have less than $1,000, SPRXX doesn’t meet the yield and expense ratio thresholds we laid out, but it doesn’t have an investment minimum.