A stablecoin's reserves are the assets an issuer holds behind its coins. They are usually cash and short-term US Treasuries. Reserve evidence is how you check those assets are really there. It runs from a bare website claim, to an attestation, to a full audit. Each step proves a different level of certainty.
An attestation is the rung most large coins stand on. It is an outside firm confirming that, on a set date, the reserves were worth at least as much as the coins in issue. That check is real and independent. But it describes one day, not a promise about the next. New to the idea? Start with what a stablecoin is first.
Reserves answer one narrow question: does the issuer hold the dollars behind each token? That is worth keeping apart from a different question, the one every exchange has to answer.
What actually sits in a stablecoin's reserves
A stablecoin's reserves are the pile of assets an issuer keeps so it can pay holders back at a dollar. The safest reserves are cash and short-term US Treasuries. They stay near face value and turn into dollars fast. Some issuers also hold repos, or riskier assets. That mix is what really sets the risk.
Not every dollar of backing is equal. What matters is how fast the reserves turn into dollars. Cash and short-term Treasuries can be sold in seconds, so the issuer can always pay out; slower assets can leave it unable to pay when everyone redeems at once. The Bank of England puts the deal plainly. Whoever issues the coin should hold the same value in real assets, and the holder has the right to swap back (source: Bank of England stablecoin explainer).
So the composition of the reserve matters more than the words "fully backed." Cash and short-term US Treasuries are the strongest holdings. Treasuries are US government IOUs that mature quickly. Short-term secured loans called repos sit close behind. Corporate bonds, other crypto, gold, and longer loans are weaker. Their price can fall, or they can be hard to sell at full value in a panic. Take the largest dollar coin. Tether reports most of USDT's reserves in short-term US Treasuries, about $141 billion of direct and indirect exposure in early 2026, with a smaller share in other assets (source: Tether Q1 2026 reserves attestation).
What backs a coin also shifts with the type of stablecoin you hold. A fiat-backed coin keeps cash and bonds at a company. A crypto-backed coin locks other tokens in code. Many issuers now park the bulk of reserves in government debt. So reading a report often means looking at holdings of tokenized Treasuries and money-market funds, not a vault of paper cash. Knowing what should sit in the reserve only helps if you can check it. That is where the evidence comes in.
The ladder of reserve evidence, weakest to strongest
Reserve evidence comes in levels, and they are not equal. The weakest is a bare claim on a website. Stronger is an attestation, where an outside firm checks the reserves on a date. Stronger still is a full audit. The most direct is on-chain data you can watch yourself, updated all the time.
Here is the ladder, from the least convincing evidence to the most.
| Evidence | What it proves | Who produces it | Its main limit |
|---|---|---|---|
| Bare claim on a website | The issuer says it is fully backed | The issuer, on its own | Nobody independent has checked it |
| Agreed-upon procedures report | The reserves matched the coins on a date, as plain factual findings | An outside accounting firm | The firm gives no opinion, only the numbers it was asked to run |
| Examination attestation | An outside firm's opinion, with reasonable assurance, that reserves covered the coins on the date | An outside accounting firm | One date only, and just the reserve claim, not the whole company |
| Full financial audit | The whole company's financial statements over a full period | An independent auditor | Rare for stablecoins, usually done once a year, and it does not by itself report on internal controls |
| On-chain, real-time data | The reserve balance a feed reports on-chain, refreshed continuously | The issuer plus an oracle network | Leans on the feed and on what the custodian reports |
Walk up the rungs and the confidence grows. A bare claim is marketing until someone outside tests it. An agreed-upon-procedures report is a real step up. An outside firm runs a set of checks and reports the figures. It stops short of giving an opinion, though. An examination goes further. Here the firm gives an opinion, with reasonable assurance, that the reserve claim is fairly stated. A full audit is broader again. It covers the whole business, not the reserve line alone.
The top rung is the most direct. On-chain proof of reserves publishes the balance straight to a blockchain. Anyone can watch it. Tools like Chainlink's proof of reserve pull custodian and wallet data on-chain. A smart contract can then confirm backing all the time, and even refuse to mint new coins when the reserve looks short (source: Chainlink Proof of Reserve). For crypto-backed coins you can often see the collateral on-chain yourself. That is the most open case of all. For fiat-backed coins the dollars sit in banks off-chain. So even a live feed still leans on what the bank and custodian report. Most large dollar coins today stand on the report rung, and it is the one people most often misread, so it helps to learn how to read a reserve report.
Attestation vs audit: what each one really checks
An attestation is an outside firm confirming one claim: that the reserves were worth at least the coins in issue, on a stated date. An audit is far wider. It examines the whole company's financial statements and weighs whether the business can keep operating. Think of an attestation as a spot-check. An audit is the full exam.
The two words get mixed up, so it helps to pin them down. In the US, these checks follow standards set by the American Institute of CPAs. Its criteria for stablecoin reporting are the basis for the work (source: AICPA criteria for stablecoin reporting). Outside the US, many firms follow a standard called ISAE 3000. The firm examines one claim from the issuer, usually that reserve assets were worth at least the tokens outstanding on the date. It confirms balances with banks and custodians. It checks the coin count against the blockchain. Then it signs a report tied to that date.
The big dollar coins report on a regular clock. Circle has a Big Four accounting firm provide monthly third-party assurance that USDC's reserves are worth at least the coins in circulation, and it publishes what is in the pool (source: Circle transparency disclosures). Tether publishes its USDT report every quarter, signed by BDO. Both are checks by an outside firm, and both are useful. But neither one, on its own, is a full financial audit.
| Attestation | Full financial audit | |
|---|---|---|
| Scope | One claim: reserves versus coins | The whole company's financials |
| Time covered | A single date, a snapshot | A full period, usually a year |
| Internal controls | Not tested | Considered when planning; formally reported on only in a separate controls audit |
| Other liabilities and going concern | Not assessed | Other liabilities assessed; going concern evaluated |
| How often | Monthly or quarterly | Yearly, if done at all |
A monthly check is genuinely useful. It catches a shortfall far sooner than a yearly report would. It just answers a narrow question. A full audit is broader, but it has edges too: on its own it covers the financial statements and going concern, while formally testing and reporting on internal controls is a separate, integrated controls audit that accelerated and large accelerated public-company filers face, not something every financial-statement audit includes. A full audit is also rare for stablecoins, though new rules are pushing the largest issuers toward one. Even the strongest monthly report has hard limits. Knowing them is the difference between reading a report as evidence and reading it as a comfort blanket.
What an attestation does not tell you
An attestation confirms one claim on one day, so its limits are built in. It does not promise they looked the same the week before, or the day after. It does not test the issuer's other debts, its controls, or whether it can keep running. And it says nothing about whether you can redeem for a dollar today.
Think of it like a health inspector's visit. A clean report tells you the kitchen passed on the day the inspector stood in it. It does not promise the kitchen was clean last Tuesday. It does not promise it will be clean tomorrow. A reserve report is the same kind of dated spot-check. That is why the date on the report matters, and why a monthly check beats a yearly one.
The clearest lesson came from USDC in March 2023. Circle had about $3.3 billion of USDC reserves, roughly 8% of the total, parked at Silicon Valley Bank. The bank failed on a Friday. The reserves were fully there, and earlier reports had shown as much. But the banks were shut for the weekend, so Circle could not move the money. USDC slid to about $0.86. It recovered sharply once the US government guaranteed all of the bank's depositors that Sunday, then fully recovered once Circle began processing redemptions the next day (source: Federal Reserve note on Silicon Valley Bank and stablecoins). A check on the amount was accurate, and it still could not flag the real problem. The real problem was where the cash sat, and whether it could move.
That gap points at two more. A report does not tell you whether you can swap out at a dollar on demand. That depends on the issuer's redemption rules, and how coins are issued and redeemed is its own process with its own limits. It also says little about how an issuer's ownership and structure can create risk, even when the reserve looks full. That is a separate subject worth its own reading: stablecoin issuer risk. The takeaway is to build a habit, not to panic. Check the evidence, not the slogan, the same way you would practice basic crypto security everywhere else. There is also a second check that people often confuse with this one.
Two different reserve questions: issuer reserves vs exchange proof-of-reserves
Two very different checks both use the word "reserves," and mixing them up is common. Issuer reserves ask whether the company behind a stablecoin holds the dollars behind each token. Exchange proof-of-reserves asks whether a trading platform holds the crypto it owes its users. Different party, different question, different evidence.
| Issuer reserves | Exchange proof-of-reserves | |
|---|---|---|
| The question | Does the stablecoin issuer hold the dollars behind each coin? | Does the platform hold the crypto it owes its users? |
| Who is being checked | The coin's issuer (for example, Circle or Tether) | The exchange or custodian |
| The evidence | Reserve attestations, audits, issuer disclosures | Proof-of-reserves reports, on-chain wallet proofs |
| What it does not cover | Whether your exchange is solvent | Whether a specific stablecoin is truly backed |
The distinction is easy to lose, because the same coin can raise both questions at once. Say you hold USDC on an exchange. The issuer question is whether Circle really holds the dollars behind USDC. The exchange question is whether the platform really holds the USDC it credits to your account. A strong answer to one says nothing about the other. How a platform proves it holds customer assets is a separate topic, covered in exchange proof of reserves. It sits alongside the broader question of how exchange custody works.
On BloFin's platform, we publish proof-of-reserves attestations covering the assets we hold in custody, and the wording there matters. That report answers whether the exchange is holding the coins its users are owed. It does not speak to whether the company behind a stablecoin holds the dollars behind each token. That is a separate promise, checked with separate evidence. So when a USDC balance sits in an exchange account, two claims stand behind it: the issuer's reserves and the platform's custody. You can read BloFin's proof of reserves for the exchange side, and still check the issuer's own reports for the coin itself. Even a full reserve can sit behind risk in the issuer's own structure, which is worth weighing too. Rules are now starting to force a minimum standard on both.
How regulation raises the floor
Rules are starting to set a floor under reserve evidence. In the US, the GENIUS Act makes payment stablecoins hold high-quality liquid reserves. It also makes them publish regular reserve reports. In the EU, MiCA makes issuers hold proper, segregated reserves and disclose them. Neither framework lets a payment coin pay interest to the people who hold it.
Start with the US. The GENIUS Act, Public Law 119-27, is the first federal law written just for payment stablecoins. It was signed in 2025 (source: GENIUS Act, Public Law 119-27). It sets three main rules. A payment stablecoin must be fully backed by high-quality liquid assets, like cash and short-term Treasuries. Issuers must publish monthly reserve reports checked by an outside firm. And the largest issuers must add a yearly audit. One point trips people up, so it is worth being exact. The law is signed, but not fully in effect yet. It switches on at the earlier of January 18, 2027, or 120 days after regulators finish the detailed rules. As of mid-2026, those rules are still being written.
Europe moved first. Its Markets in Crypto-Assets rules, known as MiCA, have applied to stablecoins since June 30, 2024 (source: European Banking Authority statement on MiCA). MiCA makes an issuer hold a reserve that fully backs the coins. It makes the issuer keep that reserve legally separate from the company's own money, so its creditors cannot touch it if the issuer fails (source: ESMA on the MiCA reserve rules). Holders get a right to redeem. Issuers must also publish a rulebook, describing what the reserves are and where they sit. The shared idea on both sides of the Atlantic is simple: turn "trust us" into "show us, on a schedule." That is the same habit a careful holder already uses. It fits how you would weigh reserve and issuer risk against everything else you hold in crypto.
Frequently asked questions
Why don't the big stablecoins get a full financial audit instead of an attestation?
A full audit is slower and costs more. It asks a firm to judge the whole business, not just the reserve. So for years, issuers chose the faster attestation. It was also newer ground, since standard criteria for stablecoin reporting only arrived recently. That is changing. The largest issuers are moving toward full audits, partly because new US rules will require a yearly audit above a size threshold. Until an issuer publishes one, a monthly check by a trusted firm is the strongest evidence most coins offer.
How can I find and check a stablecoin's reserve report myself?
Start on the issuer's own site. Most large issuers keep a transparency or reserves page. Open the latest report and check four things. First, the date, because recent beats old. Second, who signed it, because a named firm beats an unsigned page. Third, what the reserves actually are, because cash and short-term Treasuries beat vague or risky assets. Fourth, whether the number of coins matches the reserves. Reading a report line by line is a skill of its own, but those four checks catch most of the problems.
Does a reserve attestation mean I can always redeem my coin for a dollar?
No. An attestation says the reserves existed on a date. It does not promise you can swap out instantly at a dollar. Redemption depends on the issuer's own rules. Those can include minimum amounts, who qualifies, or processing time. And in a rush, even a fully backed coin can trade a little below a dollar before it recovers. The right to redeem, and the practical way to do it, are their own topic. It is worth reading before you cash out directly with an issuer.
What is a real-time or on-chain proof of reserves?
It is reserve evidence published straight to a blockchain, and refreshed all the time, rather than in a monthly document. For crypto-backed coins, you can often see the collateral on-chain yourself. That is the most open case. For fiat-backed coins, oracle feeds pull the bank or custodian balance on-chain. So contracts and users can check backing in close to real time. It is more frequent than a monthly report, which is its strength. But it still depends on the feed, and on what the custodian actually reports.
If an attestation is only a snapshot, is it worth anything?
Yes, quite a lot. A recurring report by a trusted firm is far stronger than a bare claim. An outside party confirms balances with banks. It checks the coin count against the chain. And it puts its own name and license at risk. A monthly clock also catches a shortfall sooner than a yearly report would. The trick is to read it for what it is: strong evidence about one date. Do not stretch it into a guarantee about every other day.
Are a stablecoin's reserves insured like money in a bank?
Usually not. In the US, an insured bank deposit is protected up to $250,000 per depositor if the bank fails (source: FDIC deposit insurance). A stablecoin reserve is not a deposit. It carries no such guarantee for you, even when some of the cash behind it sits in insured banks. If the issuer cannot cover redemptions, there is usually no government backstop to make holders whole. That is a big part of why reserve quality, and clear current evidence, matter so much.
Researched and written by the BloFin Academy editorial team with AI-assisted drafting. Updated July 2026. Primary sources: the Bank of England, Circle, Tether's Q1 2026 reserve attestation, the American Institute of CPAs, the US Federal Reserve, the text of the GENIUS Act (Public Law 119-27), the EU Markets in Crypto-Assets Regulation, and the FDIC. All facts independently verified against cited documentation current as of July 2026.
This article is educational and general in nature, not financial, investment, tax, or legal advice. Stablecoins carry risk, including loss of value and loss of access, and no stablecoin is guaranteed to hold its peg or to be redeemable on demand. Do your own research, and consider a licensed professional before acting. BloFin does not provide investment advice.