An fsCOIN is a type of cryptocurrency meant to reduce price volatility and provide users with a reliable store of value. Like cash, it has no maturity, but unlike cash, it is neither a unit of account nor a widespread medium of exchange. Financial accounting standards are evolving regarding how to report these digital assets. For example, a determination as to whether an fsCOIN qualifies as a “cash equivalent,” such as a certificate of deposit, money market mutual fund (MMF), or 3-month Treasury bill, would be based on its (1) liquidity, (2) transparency, (3) level of reserves, (4) price stability, (5) redemption attributes (e.g., notice requirements, costs, limits, and counterparty, such as the issuer or an exchange), (6) intended use as either an investment or short-term means of meeting cash needs, and (7) users’ trust (Hampl and Gyönyörová 2021).9 Currently, fsCOINs are used mainly to expedite trading, lending, and borrowing other digital assets (President’s Working Group on Financial Markets et al. 2021). Speculators and investors also use them as collateral to leverage positions and to buy and sell digital assets in a distributed ledger environment without the need for fiat currencies and traditional financial institutions.

fsCOINs are not legal tender, and their issuers are independent of any central bank. Given their diminutive relative size, they are insignificant sources of demand for nations’ goods and services. Therefore, they are not major causes of inflation or deflation. With proper reserves to back them and seamless operations, fsCOINs have the potential to serve as complements of nations’ M2 money supplies.4 Furthermore, their issuance and use provide incremental testing grounds for innovative payment platforms and features, such as interoperability with other payment systems, user-friendliness, user-acceptance at the wholesale and retail levels, and an ability to comply with “Know Your Customer” (KYC), “Anti Money Laundering” (AML), and “Combatting the Financing of Terrorism” (CFT) regulations.

Critical to an fsCOIN’s value are its issuance and redemption rules. Issuance relates to controlling the number of fsCOINs in circulation to prevent over- or under-supply; redemption concerns the ability to satisfy holders’ demands to convert them to their pegged currencies.5 Because an fsCOIN’s value is determined by the forces of supply and demand, changes in demand (supply) must be met by an equivalent and offsetting change in supply (demand). Therefore, every fsCOIN has a risk-bearer who enjoys gains when demand rises and absorbs losses when it falls.

The main U.S.-dollar-backed fsCOINs are USD Coin (USDC), Binance USD (BUSD), Pax Dollar (USDP), and Geminin Dollar (GUSD). Among the significant non-U.S.-dollar-backed fsCOINs are Tether (USDT) and TrueUSD (TUSD). Multi-collateral Dai (DAI)6 and Liquidity USD (LUSD) are backed by cryptocurrencies (e.g., Bitcoin and Ether) and minted and burned by smart contracts. Algorithmic fsCOINs have no asset backing. Instead, smart contracts regulate their supplies and demands to ensure currency pegs are maintained. A popular algorithmic fsCOIN is Frax (FRAX).7 Finally, sUSD is an fsCOIN backed by the Synthetix Network Token (SNX), on which users stake SNX tokens as collateral to mint sUSDs. As a result, an sUSD’s value is supported by the staked SNX tokens.

Table 1 shows the top ten fsCOINs’ market capitalization on 16 January 2024. The top two had a combined value greater than $120 billion, which exceeded by a considerable amount JPMorgan Prime Money Market Fund, which had roughly $79 billion in assets (J.P. Morgan Asset Management 2024).

The safety and liquidity of an fsCOIN is a function of the quantity and quality of its collateral backing and the depth of its secondary markets (Hampl and Gyönyörová 2021).8 The safest fsCOIN is fully collateralized by safe assets denominated in the pegged currency, which are (1) short-term, (2) highly liquid, and (3) readily convertible to known amounts of cash, with minimal risk of their values changing. These reserve assets include deposits at other financial institutions (e.g., commercial banks); Treasury bills; commercial paper; precious metals, such as gold; cryptocurrency deposits; and other “cash equivalents."9 Nevertheless, even with 100% reserve backing, fsCOINs can lose value if issuers become insolvent or illiquid owing to:10

To ensure that equity-financed or debt-financed losses do not jeopardize an issuer’s solvency, the reserves backing an fsCOIN’s liabilities could be segregated and put into custody accounts, so they are unencumbered by any potential claims (Adrian and Mancini-Griffoli 2021).11

To moderate liquidity, credit, and counterparty risks, fsCOIN holders may be able to purchase deposit insurance (if available) or credit default swaps (CDS) on fsCOIN issuers, but these solutions only serve to shift these risks from fsCOIN holders to insurance companies and CDS counterparties.12 In 2021, the U.S. President’s Working Group recommended legislation that would allow only financial institutions with insured deposits to issue, redeem, and maintain fsCOINs (President’s Working Group on Financial Markets et al. 2021).

Because fsCOINs’ risk–return profiles are comparable to those of regulated bank deposits and other highly liquid money market assets, “regulation equality” implies that fsCOIN issuers should abide by similar (or identical) rules as banks or MMFs (Anadu et al. 2023; Catalini and Shah 2021) for: (1) liquidity, (2) equity, (3) loan concentration, (4) operational quality,13 (5) consumer protection, (6) stress testing, and (7) regulations governing transaction monitoring (e.g., KYC and AML rules), reporting suspicious transactions, and combating the financing of terrorism (CFT) (Bains et al. 2022). Owing to fragmentation and the decentralized nature of fsCOINs, achieving these goals is likely to be difficult, if not impossible, unless broad regulatory powers can be brought to bear on issuers, cryptocurrency exchanges, custodians, governance bodies, wallet providers, network validators, client fund managers, and market makers.

At the macroeconomic level, it is not clear that a monetary system centered around one or more digital currency networks would provide the optimal amount of liquidity to maintain solid real GDP growth with low inflation and an adequate emergency liquidity-funding facility. These concerns are reinforced by the uncertainty that these networks would be interoperable (Brunnermeier et al. 2019).

Because fsCOINs are uninsured and their convertibility is uncertain, they may not be universally accepted in exchange for goods, services, or other cryptocurrencies. Therefore, issuers may need incentives to induce customers to use them. Inducements could come from anonymity or opportunities for customers to transact payments and receipts outside the traditional financial system. They might also be in the form of better financial services or higher interest rates.

fsCOIN issuers are particularly susceptible to runs, regardless of whether the causes are well-founded in fact. Suspicions that the reserves backing an fsCOIN are insufficient, illiquid, or, in some other way, threatened could cause holders to convert them to safer assets, such as the currencies backing them, financial instruments denominated in safe fiat currencies, or secure cryptocurrency-denominated deposits. To meet fsCOIN holders’ demands during a run, issuers would be forced to convert their reserve assets to the pegged currency. Many of these reserves are held as uninsured bank deposits14 and, owing to their size, often exceed insurance limits, which makes them particularly susceptible to runs. Just as fsCOIN issuers would be forced to liquidate assets to meet fsCOIN holders’ demands during a run, the banks and other financial institutions in which fsCOIN issuers hold their reserves would be forced to do the same, draining funds from the interbank market and further increasing the supply of financial assets, resulting in lower asset prices (Klages-Mundt et al. 2020; Morgan 2022).15

Runs on fsCOIN issuers would not directly deplete the financial system’s liquidity because funds would be shuffled from one financial institution to another. Nevertheless, compression in asset prices could affect the solvency and liquidity of individual financial institutions, and rising interest rates could further reduce financial intermediaries’ profits, resulting in loan contraction.

The run on Terra in May 2022 negatively impacted other algorithmic-backed and asset-backed fsCOINs, such as Tether. On the positive side, the run on Terra resulted in net inflows to safe fsCOINs, such as USDC (Anadu et al. 2023). Similarly, in March 2023, USDC (i.e., USD Coin) experienced significant outflows when holders learned of its uninsured deposits held at SVB. USDC was considered among the safest reserves of all the fsCOINs, consisting mainly of U.S. Treasury securities, bank deposits, and MMFs. Nevertheless, news that about eight percent of these assets were held as uninsured deposits at bankrupt SVB triggered capital flight from USDC, which ignited outflows from Dai and Frax,16 for which reserves included extensive holdings of USDC.

An interesting commonality between the 2022 run on Terra and the 2023 run on USDC was that capital fled from fsCOINs to other fsCOINs, primarily via centralized exchanges, not from fsCOINs to traditional money market investments, such as MMFs. Investors largely replaced relatively risky Terra and USDC with fsCOINs perceived as safer, such as Tether (USDT) (Anadu et al. 2023). An equally interesting consequence of the Terra and USDC runs was that fsCOINs considered relatively safe beforehand were perceived as relatively risky afterward, and fsCOINs considered relatively risky beforehand, such as USDT and TUSD, were perceived as relatively safe afterward.