The traditional asset landscape contains two distinct relationships between an asset and the value it represents: direct value (the asset is its value) and declared backing (the asset is a claim on an underlying, soft-enforced). This document maps the full landscape, locates each asset type within it, and examines the empirical record of how the declared-backing relationship behaves under stress.
Most assets that present themselves as "backed" — gold certificates, ETF shares, fiat-pegged stablecoins, wrapped cryptocurrencies, bonds, structured notes, bank deposits — operate under soft backing: the backing relationship is real as a stated claim, but its enforcement depends on institutional honesty, custodial diligence, regulatory oversight, legal recourse, audit, attestation, or active market liquidity management. None of these mechanisms produces a protocol-level invariant that makes the rate equal the underlying by construction.
The empirical record demonstrates that soft enforcement fails under stress — the Tether reserve composition findings (NYAG settlement, February 2021), the TerraUSD/Luna collapse (May 2022), the USDC depeg during the Silicon Valley Bank failure (March 2023) — and that the price of these assets fluctuates around their declared rate rather than equaling it. The fluctuation is the structural test: a backing relationship maintained by market mechanisms must produce observable deviation; a backing relationship maintained by protocol invariant cannot, because the protocol rejects transactions that would produce deviation. Every declared-backed instrument currently in circulation falls in the first category.
This document establishes the taxonomy that distinguishes these categories rigorously, examines the historical record of soft-backing failure across three documented cases, traces the chain of unbacking that produces structural fragility in fiat-pegged stablecoins and bank deposits, and develops the diagnostic test that allows any reader to evaluate any "backed" instrument's structural status independently.
Across commodities, fiat currencies, crypto-native assets, and structured financial instruments, there are two distinct ways in which an asset can stand for value. These two relationships are foundational; every asset category in current circulation operates under one of them.
The asset is the value-bearing thing. It is not a claim on anything else. Its price is established by the market — by what buyers and sellers agree it is worth. There is no backing relationship to enforce, because there is nothing the asset is a claim on. The asset stands for itself.
Direct-value assets cover both physical substances and protocol-defined instruments. Gold trades on the market for the physical and chemical properties of gold itself — its scarcity in the Earth's crust, its durability, its conductivity, its acceptance as a unit of account across millennia. BTC trades on the market for the protocol properties of the BTC chain — its hard-capped supply, its transaction-finality model, its issuance schedule, and the political consensus around its specification. Neither carries a redemption right to anything more fundamental. Each is the most fundamental thing it is.
The asset represents a claim on something else — a physical commodity, a reserve account, an underlying portfolio, an issuer's obligation. The claim is part of the asset's structure. Its enforcement is soft: it depends on custodial honesty, legal recourse, regulatory oversight, audit, attestation, or institutional commitment. The claim is real, but the connection between the asset and the underlying admits exception — custodial failure, default, fraud, regulatory action, hacks.
Declared-backed assets cover instruments that exist by reference to an underlying. A gold certificate is a claim on physical gold held in a vault. A wrapped Bitcoin token (WBTC) is a claim on a BTC held by a custodial bridge. A bond is a claim on the issuer's obligation to pay. An ETF share is a claim on a basket of underlying holdings. A bank deposit is a claim on the bank's balance sheet. None of these is the underlying; each is a paper, on-chain, or contractual representation that points to an underlying via a chain of institutional commitments.
Gold · silver · platinum · oil · raw materials.
Traded for what they are. No backing claim. Scarcity is intrinsic to the substance and verifiable by physical possession plus assay.
Gold certificates · GLD ETF shares · commodity-backed tokens.
Declared backing: physical reserves held by a custodian. Enforcement: custodial honesty, audit, assay verification. The certificate is a paper claim on a substance that exists elsewhere.
BTC · BCH · ETH · SOL · LTC.
Traded for what they are. No backing claim. Scarcity is protocol-enforced through the consensus rules of the underlying chain.
WBTC · WETH · cbBTC · renBTC.
Declared backing: the underlying cryptocurrency held by a custodian or wrapping bridge. Enforcement: custodian honesty, bridge integrity against external attack, bridge operator integrity (the operator can mint without holding underlying, reconfigure parameters, or censor redemptions), and oracle accuracy. The wrapped token is a claim on the underlying that exists on a different chain.
Federal Reserve notes · euro banknotes · yen banknotes · pound banknotes · all national currencies in physical form, including metallic coins.
Direct-value instruments that make no operative backing claim. The dollar bill is worth a dollar; there is no underlying asset the banknote can be redeemed for at a fixed rate. Enforcement of the unit-of-account framework comes from legal tender laws, central bank operations, foreign-exchange market acceptance, and political and economic policy support — not from any redemption right.
Historical note. Pre-1971, fiat currencies operated under declared backing — redeemable for gold at fixed rates under the Bretton Woods framework — and would have sat in column B as claims on gold. The Nixon Shock of August 1971 severed convertibility, moving fiat from declared-backed to direct-value. The "full faith and credit" language that remains in legal frameworks is a political and policy anchor, not a redemption-mechanism backing claim. The chain of unbacking begins here: physical fiat is the layer at which the historical redemption mechanism to a substantive underlying (gold) was cut.
Checking accounts · savings accounts · money-market accounts. The digital-ledger layer of the financial system.
Declared backing: the fiat money (banknotes and coins, primarily, or other valuables) the depositor placed with the bank. The bank holds the deposit and is contractually obligated to return it on demand or per the deposit agreement; the depositor's account balance is a claim against the bank for that return. There is no free deposit — the bank's role is custodial-plus-lending, and what the depositor holds is a claim, not the deposited asset itself.
Enforcement: deposit insurance (FDIC/FSCS/etc., up to specified limits), bank solvency, regulatory oversight, and ultimately the central bank's lender-of-last-resort function. The fractional-reserve property. Banks do not hold the full deposit base in physical-fiat reserves; only a fraction is held against redemption demands. Withdrawal limits (daily caps, transaction-size restrictions, branch availability) restrict the operative redemption mechanism for typical holders. The chain of unbacking continues: a bank deposit is a fractionally-backed claim on Layer 1 physical fiat, which itself has no underlying.
The same ledger entries that appear as bank deposits in the row above — viewed from the perspective of stablecoin reserves rather than from the perspective of the individual depositor.
Digital fiat is structurally a claim (on the physical fiat held by the bank, fractionally) but operatively functions as direct value for most participants and most use cases. Most digital fiat will never be redeemed for physical fiat — it gets transferred between digital accounts within the banking system. The unit-of-account function operates at the digital-ledger layer, not at the physical-fiat layer.
For the purposes of being the underlying that stablecoins claim backing by, digital fiat functions as the direct-value reference asset — stablecoins' reserves are denominated in digital fiat (cash equivalents, demand deposits, treasury bills), not in physical banknotes. The chain of unbacking compounds: digital fiat is a fractional claim on physical fiat, which makes no backing claim; stablecoins (column B opposite) declare backing by digital fiat, adding a third layer.
USDT · USDC · FDUSD · TUSD · other fiat-pegged stablecoins.
Declared backing: USD-denominated reserves consisting of digital fiat (cash equivalents, treasury bills, commercial paper, and other instruments held in bank accounts). Enforcement: issuer attestation, periodic reserve reports, primary-market mint and redeem operations restricted to large institutional clients.
Operative note. For typical holders, the backing claim is declared but not operatively accessible — primary-market redemption is gated to institutional clients. Open-market trading near the declared rate is maintained by arbitrage pressure from those large redeemers, not by enforceable redemption rights for retail. The operative restriction is a property of the soft-enforcement layer, not a different structural category — the asset is still a declared-backed instrument; the enforcement mechanism happens to restrict who can actually exercise the redemption right.
ERC-20, BEP-20, SPL, and other chain-native token standards without a peg. Most altcoins.
Traded on market value. No backing claim. The token contract typically accepts arbitrary mint instructions from the issuer's controlling address — the issuance function has no structural input constraint, so the issuer can mint any amount at will. There is no mechanism that would anchor price to any underlying, because the supply itself is unbounded by design.
Bonds · notes · structured products · ETF shares · closed-end fund shares.
Declared backing: issuer obligation to pay, or underlying portfolio holdings. Enforcement: legal recourse via courts, regulatory action, contractual remedies.
Each asset sits in one position. Direct-value assets (column A) stand for themselves — gold is gold, BTC is BTC, a banknote is a banknote — and require no backing claim because there is nothing more fundamental for them to be a claim on (or, in the case of physical fiat, the historical claim to gold was severed and no replacement underlying was introduced). Declared-backed assets (column B) are claims on an underlying named in column A — a gold certificate is a claim on physical gold, a bank deposit is a claim on physical fiat, a stablecoin is a claim on digital fiat, a bond is a claim on the issuer's obligation. The structural distinction is whether the asset asserts a relationship to something else, or stands alone (or, in the borderline cases, operates as if it stands alone despite a structural claim).
Rows 3a and 3b trace the chain of unbacking visually. Reading downward through the rows pairs each claim with its underlying:
The chain compounds. Each generation of currency holds only a fraction of what would be needed to honor full redemption of the next generation up. Banks do not hold the full deposit base in physical-fiat reserves; only a fraction. Stablecoin issuers hold reserves at banks (digital fiat), which are themselves fractional claims on physical fiat. Beyond the layers shown in the diagram, the financial system extends the cascade further — credit money is issued by banks at multiples of their reserve base (typically around 10:1), structured products and derivatives reference credit and deposits, and the resulting claim supply far exceeds the physical-fiat base that nominally underlies it. The system functions because most holders do not attempt simultaneous redemption, and is held in place by institutional support (deposit insurance, lender of last resort), legal framework, and broad public trust in the unit-of-account convention. Section IV develops the cascade in structural detail; Section III's case studies show what happens when one layer of the cascade is stressed.
The Section I diagram operates at the relationship layer — direct value or declared backing. The Section II framing reorganizes the same landscape into two distinct structural layers based on what each asset is in relation to the others. The relationship view and the layer view describe the same landscape from different angles; both are useful, and the layer view makes clear which assets are the substrate of the system and which are claims on that substrate.
Assets that have value in themselves, not by reference to anything else. They are scarce by nature, value-bearing intrinsically, and serve as units of account in their own right. They are not backed — they don't need to be, and there is nothing more fundamental for them to be backed by.
Examples: Gold. Silver. Platinum. Oil. Raw materials. BTC. BCH. Historical hard currencies (gold coins, silver coins). Pure substances and the original cryptocurrencies belong here.
These assets can serve as the backing substrate for derivative claims in Layer 2. Gold backs gold certificates. BTC backs WBTC. The Layer 1 asset itself is the underlying; the Layer 2 instrument is the claim on it.
Instruments that represent a claim on a Layer 1 asset (or on an issuer's solvency, which references underlying assets). The claim-to-underlying relationship is enforced by soft mechanisms: custodial honesty, institutional commitment, legal recourse, regulatory oversight, accounting practice, audit and attestation, or active market liquidity management.
Examples: Gold certificates and GLD ETF (claims on gold). Wrapped Bitcoin / WBTC (claim on BTC, enforced by a custodian). USDT and USDC (claims on USD reserves, enforced by issuer attestation). Bonds (claims on issuer's obligation to pay). Bank deposits (claims on the fiat held by the bank). Structured notes and ETF shares.
The claim is real and the underlying is real, but the connection between them admits exception. Custodians can lie or fail. Issuers can default. Wrapping bridges can be hacked, but can also be operated dishonestly — the bridge operator can mint wrapped tokens without holding the underlying, refuse redemptions, dilute reserves through undocumented issuance, or reconfigure the bridge's parameters after deployment. Banks can collapse. Each of these enforcement mechanisms is real and often functional, but each is fragile under stress — which Section III documents through three specific historical cases.
The two layers describe two different positions in the asset taxonomy. Layer 1 assets are the substrate — gold, BTC, BCH, raw commodities — value-bearing in themselves. Layer 2 assets are claims on the substrate — gold certificates pointing to gold, WBTC pointing to BTC, USDT pointing to USD reserves, bank deposits pointing to fiat held by the bank. The claim is the asset's structural identity; the enforcement is what holds the claim-to-underlying relationship together.
Layer 1 pure assets sit outside the claim relationship entirely. They are not derivative claims at all; they are the substrate that derivative claims reference. Gold is not a "competitor" to a gold certificate; gold is what gold certificates are claims on. This distinction matters when evaluating any "backed" instrument: the question is not whether the underlying exists (it usually does) but how the connection between the claim and the underlying is maintained, and what happens when that connection is stressed.
The taxonomy developed in Sections I and II is a structural framework. Whether it describes reality requires looking at what has actually happened to soft-backed instruments under stress. Three cases from the past five years are sufficient to establish that the structural fragility identified in the taxonomy is not theoretical: it is the observable behavior of these instruments under stress, documented in regulatory settlements, court filings, central-bank research, and the issuers' own public disclosures.
The three cases — Tether and the New York Attorney General settlement (February 2021), the TerraUSD/Luna collapse (May 2022), and the USDC depeg during the Silicon Valley Bank failure (March 2023) — each demonstrate a different failure mode of soft enforcement. Together they cover the three primary mechanisms by which a soft-backed asset's relationship to its underlying can break: the issuer misrepresents the backing (attestation failure), the algorithmic mechanism that maintains the peg fails under stress (model failure), and the institutional infrastructure holding the backing fails (custodial-layer failure). These are not three exceptional incidents in an otherwise functional system; they are three documented instances of the same structural property — soft enforcement — failing in the ways that soft enforcement permits.
Tether Limited issued USDT, a US-dollar-pegged stablecoin, with the public representation that each token in circulation was backed 1:1 by US dollars held in reserve. The claim was made consistently across Tether's website, marketing materials, and public statements throughout the period 2014–2018. The implicit promise to USDT holders was straightforward: a USDT held in a wallet represented a US dollar held in a Tether bank account, and could in principle be redeemed at that 1:1 rate.
The New York Attorney General opened an investigation in 2018–2019 into Tether and Bitfinex (the cryptocurrency exchange operated by the same parent entities — iFinex Inc. and DigFinex Inc. — as Tether). The investigation found that at multiple points during 2017 and 2018, Tether did not hold reserves sufficient to back USDT in circulation. The NYAG's findings, published in the February 2021 settlement, stated explicitly: "Tether's claims that its virtual currency was fully backed by U.S. dollars at all times was a lie." The settlement required iFinex and Tether to pay $18.5 million, cease trading with New York customers, and submit to ongoing reporting requirements. Neither entity admitted wrongdoing.
Eight months later, in October 2021, the U.S. Commodity Futures Trading Commission separately fined Tether $41 million for making false statements regarding the 1:1 backing of USDT during the period October 2016 through February 2019. The CFTC's order identified that during that period, Tether maintained the 1:1 USD reserve claim in its public statements while holding reserves that included loans, securities, and other non-cash assets, with cash reserves at times constituting less than half of USDT in circulation.
Tether's first published reserve attestation, released in May 2021 after the NYAG settlement, disclosed that 49% of reserves were held in unspecified "commercial paper" — a category that subsequent disclosures (including documents released through New York FOIL requests in June 2023) showed included substantial holdings of Chinese commercial paper, including instruments issued by Industrial & Commercial Bank of China and China Construction Bank. The reserve composition that emerged in disclosure differed substantially from the "fully backed by U.S. dollars" representation that had been Tether's public position for most of the prior seven years.
USDT never lost its peg during this period in any sustained way. Open-market trading in USDT continued near $1, and Tether's primary-market redemption mechanism (available only to large institutional clients) was not stress-tested at scale. The misrepresentation of backing was documented through regulatory investigation rather than discovered through a redemption run.
Soft enforcement via attestation permitted the issuer to maintain a backing claim for years that the regulatory record subsequently established was false. The enforcement layer — issuer self-disclosure with no third-party verification of reserve composition until after the regulatory action — created the conditions for the misrepresentation. The structural property is not that Tether is uniquely dishonest; it is that the enforcement mechanism for attestation-backed instruments does not require honesty to function in the absence of stress. Market liquidity (open trading of USDT near $1) maintained the appearance of backing for years while the underlying reserves did not match the claim.
The Tether case is therefore not the failure mode most associated with stablecoins in public discourse — a dramatic depeg — but a quieter and structurally more troubling failure mode: the backing claim and the actual backing diverged, and the divergence was sustained through institutional opacity rather than corrected through market mechanism.
Primary sources: Office of the New York Attorney General, Settlement with Bitfinex and Tether, February 23, 2021. U.S. Commodity Futures Trading Commission, Order against Tether Limited, October 15, 2021 (CFTC Docket No. 22-04). In re Tether and Bitfinex Crypto Asset Litigation, Consolidated Amended Complaint, U.S. District Court for the Southern District of New York, 2021.
Supporting: CoinDesk reporting on FOIL document release, June 2023. Tether reserve attestations, May 2021 forward. Griffin, John M.; Shams, Amin. "Is Bitcoin Really Un-Tethered?" Journal of Finance, October 2020.
TerraUSD (UST) was a US-dollar-pegged stablecoin issued on the Terra blockchain. Unlike Tether or USDC, UST was not backed by USD reserves held by a custodian. Its peg was maintained by an algorithmic arbitrage mechanism with a sister token, LUNA: holders could always burn $1 of UST to mint $1 of LUNA, or burn $1 of LUNA to mint $1 of UST, regardless of the open-market price of either. The system was promoted as a "decentralized stablecoin" — one that did not depend on traditional banking infrastructure or custodial backing, but rather on an economic mechanism that would maintain the peg through arbitrage incentives. At its peak (May 2022), UST had reached approximately $18 billion in market capitalization, making it the third-largest stablecoin in circulation. Approximately 75% of UST circulating supply was held in Anchor Protocol, a Terra-native lending product that paid approximately 20% annual yield on UST deposits.
On May 7, 2022, a series of large UST withdrawals from the Curve Finance 3pool (a key liquidity pool where UST was traded against other stablecoins) reduced UST liquidity by approximately 6% of pool depth, totaling around $84 million in withdrawals. The withdrawals triggered an initial depeg from $1 to approximately $0.985, which prompted further withdrawals as Anchor Protocol depositors began exiting their positions to avoid being caught in a larger depeg event.
Over the next week — May 9 through May 15, 2022 — the algorithmic mechanism that was supposed to defend the peg instead accelerated the collapse. As UST holders attempted to redeem UST for LUNA at the 1:1 rate, LUNA supply expanded at an exponential pace. LUNA's circulating supply went from approximately 350 million tokens before the depeg to over 6.5 trillion tokens within days. LUNA's open-market price collapsed from approximately $87 to approximately $0.00005 over the same period. The arbitrage mechanism that was supposed to defend UST's peg instead destroyed both tokens: UST settled near $0.20 (and would later trade near $0.01), and LUNA effectively went to zero.
Over $50 billion in combined UST and LUNA market value was destroyed in approximately seven days. Anchor Protocol depositors lost the bulk of their holdings. The Luna Foundation Guard's Bitcoin reserve — approximately 80,000 BTC that had been accumulated specifically to defend the peg in a crisis — was deployed during the collapse without successful effect; the reserve was inadequate to absorb the redemption pressure.
Soft enforcement via algorithmic arbitrage depends on the algorithm's economic assumptions holding under stress. The Terra mechanism assumed that arbitrageurs would profitably defend the peg when UST traded below $1 (by burning UST for $1-worth of LUNA and selling the LUNA at market). The assumption held under normal conditions but failed catastrophically under stress, because the arbitrage required LUNA's market value to remain stable — and LUNA's market value was the variable that depegging directly destroyed. The algorithm did not merely fail to defend the peg; the algorithm itself was the transmission mechanism through which the depeg destroyed both tokens.
The structural property: any soft enforcement mechanism that depends on the stability of the very variable it is designed to maintain is vulnerable to reflexive collapse under stress. The Terra failure was not an algorithmic bug — the code worked exactly as designed. The failure was that the design's economic assumptions did not hold when the system was tested. Models that pass under steady-state conditions can fail catastrophically when the conditions they assumed become the variable.
Primary sources: Federal Reserve Bank of Richmond, Economic Brief 22-24, "Anatomy of a Stablecoin's Failure: The Terra-Luna Case," July 2022. Liu, J., Makarov, I., Schoar, A. "Anatomy of a Run: The Terra Luna Crash." NBER Working Paper, 2023.
Supporting: On-chain mint and burn data for UST and LUNA, May 7–15, 2022 (publicly observable). Anchor Protocol TVL data, May 2022. Curve Finance 3pool transaction history, May 2022.
USD Coin (USDC), issued by Circle Internet Financial, was — and is — represented as a 1:1 USD-backed stablecoin with reserves held in cash and short-term US Treasury securities. Unlike Tether at the time of the NYAG investigation, Circle published monthly attestations of USDC reserves throughout this period, audited by reputable accounting firms. The backing was real and the attestations were accurate. USDC was generally regarded in cryptocurrency markets as the "transparent" alternative to USDT — a stablecoin whose reserve composition was well-documented and conservatively held.
Approximately $3.3 billion of USDC's roughly $40 billion in reserves (about 8% of total reserves) was held as cash deposits at Silicon Valley Bank, a major US commercial bank that primarily served technology companies and venture-capital portfolios. On Friday, March 10, 2023, SVB failed and was taken into FDIC receivership. The failure left $3.3 billion of USDC's reserve cash trapped at SVB, with uncertain recoverability depending on the FDIC's resolution process and whether the FDIC's standard $250,000 per-account insurance limit would be expanded.
Circle disclosed the SVB exposure on Friday March 10. Over Saturday March 11, USDC's open-market price fell from $1 to a low of approximately $0.86–$0.87 on major exchanges (Coinbase, Kraken, Binance, others). USDC's primary-market redemption mechanism remained operational for institutional clients, but the open market — where retail and most secondary holders interacted with USDC — priced the token at a significant discount reflecting the uncertainty about the trapped reserves.
On Sunday March 12, 2023, the Federal Reserve, U.S. Treasury, and Federal Deposit Insurance Corporation issued a joint statement guaranteeing all SVB deposits (not just those below the standard $250,000 insurance threshold). The backstop announcement effectively removed the credit risk associated with the trapped reserves. USDC's open-market price recovered to near $1 within hours of the announcement and re-pegged fully by Monday March 13.
The recovery was contingent on the federal backstop. Without the joint Fed/Treasury/FDIC action, USDC would likely have remained substantially depegged for an extended period, and a significant fraction of the trapped reserves might have been unrecoverable through standard FDIC resolution. Circle's own disclosures in subsequent filings — including its S-1 filing with the SEC in April 2025, in connection with its public-company registration — disclosed that Circle's stockholders' equity at year-end 2023 was approximately $0.34 billion. The SVB-trapped exposure of $3.3 billion was thus approximately 10× Circle's own equity. Had the backstop not been provided and the reserves been substantially lost, Circle would have been unable to make USDC holders whole from its own balance sheet.
Soft enforcement of stablecoins via custodial reserves introduces structural dependencies on the institutional infrastructure that holds those reserves. The USDC depeg was not caused by Circle misrepresenting reserves (Circle's disclosures throughout were accurate). It was not caused by an algorithmic mechanism failing (USDC does not depend on algorithmic arbitrage). It was caused by the failure of a custodial layer — a commercial bank — that held a portion of the reserves. The stablecoin's design did not anticipate the bank failure because the design implicitly assumed that the banking system functioned as a stable substrate.
The structural property: even when the backing claim is accurate and the issuer is honest, soft-backed instruments inherit the failure modes of every institutional layer they depend on. A stablecoin backed by USD reserves in banks depends on (i) the issuer's honesty about reserves, (ii) the banks' continued solvency, (iii) the broader banking system functioning, and (iv) ultimately the central bank or government stepping in if any of the above fails. Each of these layers is a point at which the relationship between the stablecoin and its underlying can fail without the stablecoin itself doing anything wrong. The USDC episode revealed that the survival of a properly-backed stablecoin under stress can depend on government intervention rather than on the stablecoin's own design.
Primary sources: Circle Internet Financial public disclosures, March 10–13, 2023. Federal Reserve, Treasury, and FDIC joint statement on SVB and Signature Bank, March 12, 2023. Federal Reserve Notes, "In the Shadow of Bank Runs: Stablecoin Dynamics," December 2025. Circle Internet Financial, Form S-1, U.S. Securities and Exchange Commission, April 2025.
Supporting: Open-market USDC price data, Coinbase and Kraken, March 10–13, 2023. FDIC receivership announcements, March 10, 2023.
Each of the three cases isolates a different failure mode that is structurally available to soft-backed assets. Tether demonstrates failure through misrepresentation — the issuer's claim about backing diverging from the actual reserves, sustained by institutional opacity rather than corrected by market mechanism. TerraUSD/Luna demonstrates failure through model breakdown — an algorithmic mechanism that was supposed to defend the peg becoming the transmission channel through which the depeg destroyed the system. USDC at SVB demonstrates failure through custodial-layer infrastructure breakdown — a properly-backed and honestly-disclosed stablecoin depegging because a bank holding a portion of reserves failed.
The three failure modes are not exhaustive but they are illustrative of the structural space: any soft-backed instrument's continued alignment with its declared backing depends on (i) the issuer's honesty, (ii) the mechanism's correctness under stress, and (iii) the underlying infrastructure's continued operation. A failure of any of these three is sufficient to break the relationship between the asset and its underlying. Hard backing — backing maintained by protocol invariant rather than institutional mechanism — removes all three dependencies at once: the protocol cannot misrepresent, cannot model a mechanism incorrectly, and does not depend on a custodial layer that can fail.
The three cases above are the strongest available empirical evidence for the structural argument the next section develops: that soft backing is not merely fragile but structurally fragile — fragile in ways that are predictable from the architecture, not exceptional in the operational history.
A fourth architecture: collateralized-debt ("CDP") stablecoins (MakerDAO/DAI-class). Distinct from the three cases above, a CDP stablecoin is minted permissionlessly by locking on-chain collateral — the most deceptive case for the diagnostic test, because it looks collateral-backed. The resolution: the collateral backs the debt position (the vault, a liability), not the circulating token. A token holder has no redemption claim on the collateral — only the ability to repay a debt or sell on a market; the token's value is market-determined and its peg breakable (the Terra case above was the algorithmic cousin). Two tests place it: by the structural test (Section V) it has no by-construction rate → soft-backed; and by the complementary unilateral-redemption test — can the holder realize base-unit value alone, with no market, oracle, or counterparty? — it fails, so the token is in substance unbacked. In the Deviant taxonomy the circulating token is therefore PTU (permissionless · no backing claim · unlimited), distinct from a custodial stablecoin's MTU; what is enforced at consensus is a debt obligation, not token backing. See ADR-0033 and asset-landscape.md.
Section IV — The cascade of unbacking. The structural argument extended from single-step chain-of-claims to multi-generational cascade. Each generation of currency in the modern financial system — paper fiat, digital fiat, credit money — is a claim on the generation below, with each layer holding only a fraction of what would be needed to honor full redemption of the layer above. Fiat-pegged stablecoins extend the cascade one layer further. The structural fragility is architectural: most claims at the top of the pyramid have no path to the direct-value base if simultaneous redemption is attempted, and the system's continued operation depends on this redemption never being collectively tested.
Section V — The diagnostic test. A binary test for distinguishing structurally maintained backing from market-maintained backing: does the asset's price equal its declared rate by construction, or does it approach the rate through market mechanisms with observable deviation? Every current "backed" asset in circulation operates under soft backing by this test.
Section VI — Implications. What "backing" means structurally as a property of an asset's design rather than as a marketing claim about an asset's stated relationships; why every declared-backed asset currently in circulation is soft-backed by structural definition; what the architecture of soft enforcement permits and what it does not; and what the taxonomy reveals about how participants should evaluate any "backed" instrument they encounter.