Imagine you could hold digital money that stays at exactly $1.00 per unit, no matter what Bitcoin or Ethereum is doing, that you can send anywhere in the world in seconds for a fraction of a cent in fees, that earns yield in decentralised finance, and that exists entirely as code on a blockchain. That is what a stablecoin is. The stablecoin market has grown from essentially nothing in 2017 to over $316 billion in total market cap by 2026, making it one of the fastest growing and most practically important segments of the entire crypto industry. This blog explains exactly how they work, why there are different types, what distinguishes USDT from USDC from DAI, and what the risks are that most guides politely skip over.
By CryptoAcademy Team | Published: 2026-04-02 | 18 min read time read | Category: Educational
Before we explain what stablecoins are, it helps to understand the problem they were invented to solve.
Bitcoin was invented as a form of digital money. But there is a fundamental tension between something being a good investment and being a good currency.
If you believe Bitcoin is going to increase dramatically in value, you have a very strong reason not to spend it. Spending a Bitcoin today on something that costs $70,000 feels different if you believe that Bitcoin will be worth $500,000 in five years. This is the story of the person who spent Bitcoin on pizzas in 2010 and never quite got over it.
At the same time, if the value of your "money" can drop 40% in three weeks, it is extremely difficult to use for practical purposes. You cannot pay salaries in something that unpredictably loses value. You cannot price goods in it. You cannot hold savings in it without the risk that your savings shrink dramatically through no fault of your own.
The crypto industry needed something that combined the speed, programmability, and accessibility of cryptocurrency with the price stability of fiat currency. Something that would hold $1.00 of value today, tomorrow, and next year regardless of what the broader market was doing.
That something is a stablecoin.
Stablecoins are a type of cryptocurrency designed to maintain a stable value, typically pegged to a reserve asset. Usually each coin is pegged 1:1 with a fiat currency like the US dollar. They retain key advantages of blockchain technology, such as efficient cross-border transfers and low transaction fees.
The result is digital cash: a form of money that anyone with a smartphone and internet connection can hold, send, and receive without a bank, that cannot be seized by a government simply by contacting a financial institution, that settles in seconds or minutes rather than days, and that costs fractions of a cent to send regardless of the amount.
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The growth of the stablecoin market is one of the most striking stories in all of finance.
The stablecoin market cap has increased from $205 billion to over $300 billion in 2025 alone, with the total supply now exceeding $316 billion as of early 2026. The market has grown by nearly $100 billion in a single year, and this follows $70 billion in growth in 2024. Stablecoins have grown to be approximately 45 times larger than they were in late 2019.
On-chain stablecoin transaction volume exceeded $8.9 trillion in H1 2025 globally.
To put that in perspective: $8.9 trillion in the first half of one year. The entire US GDP for comparison is approximately $28 trillion annually. Stablecoins are not a niche instrument for crypto traders. They are processing transaction volumes that rival or exceed many traditional financial systems.
Stablecoin issuers have become the seventh largest purchasers of US government debt. When Tether and Circle need to back their stablecoins with real reserves, they buy US Treasury bills. The stablecoin market's reserve requirements are now a meaningful force in the US Treasury market.
This transformation happened for several interconnected reasons. DeFi created enormous demand for stable on-chain liquidity. Cross-border payments in countries with weak or restricted banking infrastructure found stablecoins to be dramatically more accessible than traditional remittance channels. Traders needed a way to move between crypto positions and cash equivalents without exiting to bank accounts. And institutional investors needed on-chain dollar liquidity for emerging digital asset applications.
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Not all stablecoins work the same way. There are three fundamentally different approaches to maintaining price stability, each with different mechanics, trust assumptions, and risk profiles.
Fiat-backed stablecoins are the simplest and most widely used type. The concept is exactly what it sounds like: for every stablecoin in circulation, there is one US dollar (or dollar-equivalent) held in reserve by the issuing company.
If you hold 100 USDT, Tether is supposed to hold $100 in reserves. If you want to redeem those USDT for actual dollars, you can (subject to certain minimums and terms), and Tether will pay you from those reserves.
This model is straightforward to understand and trust, at least in principle. The risks are equally clear: you are trusting the company that issues the stablecoin. If the company lies about its reserves, mismanages them, or goes bankrupt, the peg can break.
USDT and USDC are both fiat-backed stablecoins. They are the dominant players in the market by a wide margin.
Crypto-backed stablecoins are backed not by dollars in a bank account but by other cryptocurrencies locked in smart contracts. Because cryptocurrencies are themselves volatile, these stablecoins are over-collateralised: you deposit more value in crypto than the stablecoin you receive is worth.
DAI is the primary example. To mint DAI, you lock ETH or other approved collateral in a MakerDAO vault at a minimum ratio of 150%, with a recommended ratio of 200% or more. If the collateral's value falls below the required ratio, it gets automatically liquidated to maintain the peg.
The appeal of crypto-backed stablecoins is that they do not require trusting any company. The rules are encoded in smart contracts that anyone can audit. Nobody holds the reserves in a bank account. The system runs on code.
The risk is that extreme market volatility can outpace the liquidation mechanisms, potentially causing the stablecoin to lose its peg. This risk is managed through over-collateralisation, but it cannot be eliminated entirely.
Algorithmic stablecoins attempt to maintain their peg through code and economic incentives rather than direct collateral. They adjust the supply of the stablecoin algorithmically in response to demand: when the price rises above $1, new supply is created; when it falls below $1, supply is reduced.
This type exists in theory and practice. In practice, the most prominent example of an algorithmic stablecoin is TerraUSD (UST), which spectacularly failed in May 2022, wiping out over $40 billion in value in a matter of days.
Without regulations or reserves, TerraUSD quickly lost trust, triggered a panic sell-off, and eventually collapsed. The algorithmic mechanism that was supposed to maintain the peg instead accelerated the death spiral.
The GENIUS Act, the first comprehensive US federal stablecoin law passed in July 2025, requires payment stablecoins to be fully backed by real reserves, effectively signalling that pure algorithmic stablecoins without genuine collateral backing are not acceptable for mainstream use.
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Tether's USDT is the most widely used stablecoin in the world and has been since the stablecoin market first emerged at scale. It is also the stablecoin with the most complicated history.
USDT comprises 58% of the entire stablecoin market, an amount worth over $176 billion. USDT's daily trading volumes run between $40 billion and $200 billion, making it the primary liquidity instrument in digital asset markets.
That number captures the scale of USDT's role. When someone in Turkey wants to protect their savings from lira inflation by holding something dollar-linked, they often buy USDT. When a trader in Southeast Asia wants to move between crypto positions, they park value in USDT. When a DeFi protocol needs dollar liquidity, USDT is one of the primary options. USDT is the closest thing crypto has to a universal dollar.
Tether has seen $10 billion in profit in the first three quarters of 2025 alone. The business model is simple and highly profitable: Tether issues USDT and invests the corresponding reserves in US Treasuries and other dollar-denominated assets. When US interest rates are high, earning yield on $176 billion in reserves produces enormous profits.
The controversy around Tether has centred on the reserves. For years, questions persisted about whether Tether actually held full reserves for every USDT in circulation. Regulatory settlements and enforcement actions over misleading statements about reserves added to the scepticism. Tether has moved toward more reserve transparency over time, but it has not passed the same level of independent audit scrutiny that Circle's USDC has.
The GENIUS Act represents a specific challenge for Tether. The law requires payment stablecoin issuers to be licensed entities in the United States. Tether is incorporated in the British Virgin Islands, not the US. Tether began the year by relocating to El Salvador. Binance said it would delist USDT for European Union users to comply with MiCA regulations. Multiple European exchanges delisted or restricted USDT as regulatory frameworks tightened.
This does not mean USDT is going away. Its role as the global liquidity engine for crypto trading outside US jurisdiction is substantial. But it does mean the regulatory landscape is bifurcating: USDC is becoming the preferred stablecoin for institutional and regulatory-compliant use in the US and EU, while USDT maintains its dominant position in global trading and in markets where regulatory compliance is less of a priority.
> Real-world example:
> "Use USDT for almost all trading activity across Asian exchanges. For getting capital in and out of DeFi protocols on Ethereum, USDC has become the default. Not a deliberate strategic decision, just the path of least resistance: USDT is on everything and accepted everywhere for trading. USDC is the one that works cleanly in DeFi and in situations where institutional counterparties are involved. Most people end up holding both for different purposes."
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USDC was created by Circle in partnership with Coinbase and launched in 2018. It was explicitly designed from the beginning to be the compliant, audited, transparent dollar stablecoin that regulators could be comfortable with.
USDC comprises approximately 25% of the stablecoin market with a market cap of over $74 billion. USDC's market cap grew 68% in 2025, faster percentage growth than USDT's 25%, reflecting the increasing demand for a regulated stablecoin in institutional and DeFi contexts.
The key distinguishing features of USDC compared to USDT:
Every USDC is 100% backed by cash and short-term US Treasury securities. The reserve composition is published monthly and attested to by an independent auditor. This level of transparency is considerably greater than what Tether has historically provided.
Circle is registered in the US and has been actively engaged with regulators, applying for an IPO in 2024 and operating under a framework designed to be fully compliant with US law. The passage of the GENIUS Act, which Circle supported, strengthens USDC's position as the stablecoin of choice for institutions operating within US regulatory frameworks.
USDC's share in DeFi reached 30% in 2025, reflecting its dominant role as collateral and liquidity in decentralised finance. Its use in US Treasury tokenisation and corporate treasury management has grown significantly.
The March 2023 Silicon Valley Bank incident was a defining stress test for USDC. When Silicon Valley Bank failed, it briefly became clear that Circle held a portion of USDC reserves there. USDC temporarily depegged to approximately $0.87 as the market processed the risk. When it became clear that USDC reserves were fully accessible and FDIC protections covered the deposits, USDC quickly returned to peg.
The incident demonstrated two things simultaneously: the genuine risk that even well-managed stablecoins face from their banking relationships, and the resilience of a well-structured, transparent