What Are Stablecoins?

Introduction to Stablecoins

One of the biggest barriers to using cryptocurrencies like Bitcoin and Ethereum as money is volatility. A coffee that costs 0.0001 BTC today might cost 0.00007 BTC tomorrow. For traders, that volatility is opportunity. For people who just want to send a paycheck across a border or save in a stable currency, it is a problem.

Stablecoins were created to solve this problem. They are blockchain-based tokens designed to maintain a stable value, almost always pegged 1:1 to the U.S. dollar. When you hold 1 USDT, 1 USDC, or 1 USDS, the issuer is targeting a price of $1.00 at all times.

This might seem paradoxical. Why would anyone want a cryptocurrency that does not go up in value? The answer is that stablecoins are not designed to be speculative assets. They are designed to be digital cash on rails: programmable, borderless, instantly transferable dollars that work 24/7 without a bank.

By early 2026, the total stablecoin market capitalization has grown to approximately $320 billion, up from $205 billion at the start of 2025. Stablecoins now settle more dollar volume in payments than most legacy networks. In 2025, stablecoin payment volumes hit roughly $11.1 trillion, an 85% jump from 2024's $5.99 trillion, and now rival Visa's $14.2 trillion in annualized payment volume.

Why Stablecoins Matter

Stablecoins solve several practical problems that held back crypto adoption for years.

Trading and on-chain liquidity: Before stablecoins, exiting a Bitcoin position meant selling back into fiat through a bank — slow, expensive, and often unavailable on weekends. Stablecoins let traders move into a "safe" dollar-denominated asset instantly, without leaving the crypto ecosystem. Today, the largest single trading pair on Binance is USDT/TRY (Turkish lira), which traded over $22 billion in 2024 alone.

Cross-border payments and remittances: The World Bank estimated global remittances at roughly $905 billion in 2024, with about $685 billion flowing to low- and middle-income countries. Top recipients included India ($129B) and Mexico ($68B). Traditional remittance corridors charge 5–10% in fees and can take days. Stablecoins move the same dollars in minutes, often for less than a dollar, regardless of the amount.

Dollar access in unstable economies: In countries with strict capital controls or runaway inflation — Argentina, Venezuela, Nigeria, Turkey, Lebanon — stablecoins are a lifeline. Argentina alone saw approximately $91 billion in crypto transfers in 2024, with 61.8% in stablecoins (versus a 44.7% global average). For households watching their local currency lose half its value in a year, a USDT balance is digital savings that the government cannot easily devalue.

DeFi infrastructure: Stablecoins are the unit of account for decentralized finance. Lending protocols like Aave, decentralized exchanges like Uniswap and Curve, perpetual futures venues, and yield protocols all denominate trades, loans, and collateral in stablecoins. Without stablecoins, DeFi would have to denominate every loan in volatile crypto — a non-starter for most use cases.

B2B settlement: In October 2024, Stripe acquired the stablecoin payments company Bridge for $1.1 billion, signaling that traditional payments giants now see stablecoins as core infrastructure rather than a niche experiment.

The Stablecoin Market in 2026

The stablecoin market is highly concentrated. Two issuers — Tether (USDT) and Circle (USDC) — control roughly 80% of the total supply. The competitive landscape in early 2026 looks like this:

Tether (USDT): ~$186–190 billion in circulation. Issued by Tether Limited, USDT is the largest stablecoin by far. The majority of USDT supply lives on Tron (~$78 billion, roughly 60%+ of all USDT), with the rest spread across Ethereum, Solana, and other chains. Tether's Q3 2025 BDO attestation reported holdings of $135 billion+ in U.S. Treasuries (making Tether the 17th-largest holder of U.S. government debt globally), $12.9 billion in gold, $9.9 billion in Bitcoin, and $6.8 billion in excess reserves. Tether reported over $13 billion in profit in 2024 and another $10 billion+ year-to-date through Q3 2025.

USD Coin (USDC): ~$74–77 billion in circulation. Issued by Circle, USDC is widely regarded as the most regulated and transparent major stablecoin. Reserves are held primarily in the Circle Reserve Fund (USDXX), a 2a-7 government money market fund managed by BlackRock and custodied at BNY Mellon. Circle's monthly attestations have been performed by Deloitte since January 2023 (Circle switched from Grant Thornton that month).

USDS / DAI (Sky Protocol): ~$13 billion combined. In August 2024, MakerDAO rebranded to Sky and launched USDS (1 DAI = 1 USDS) and the SKY governance token (1 MKR = 24,000 SKY). This was MakerDAO co-founder Rune Christensen's "Endgame" plan. The DAI-to-USDS migration finalized on April 7, 2026, though both tokens still circulate.

Ethena USDe: Roughly $4–9 billion in 2026, after peaking near $14.6 billion in late 2025. Launched in February 2024, USDe is a synthetic delta-neutral dollar (covered in Lesson 2). It became the fastest stablecoin in history to reach $10 billion, doing so in about 500 days.

First Digital USD (FDUSD), PayPal USD (PYUSD, ~$733M), Aave GHO (~$500M+), and Curve crvUSD (~$293M) round out the meaningful issuers.

BUSD is no longer in circulation. On February 21, 2023, Paxos halted minting of BUSD under a New York Department of Financial Services (NYDFS) order. Days earlier, on February 3, 2023, the SEC issued Paxos a Wells Notice signaling intent to allege BUSD was an unregistered security. Existing BUSD has been redeemed down toward zero.

How Stablecoins Maintain Their Peg

The mechanism a stablecoin uses to hold its $1 value is called its peg mechanism. The cleanest mental model is a coat check.

You hand the attendant your coat (deposit $1). They give you a ticket (1 stablecoin). Whenever you want your coat back, you return the ticket and they hand you your coat. As long as the coat check actually has every coat it issued tickets for, the tickets trade at exactly the value of one coat.

This is essentially how fiat-backed stablecoins work. For every USDT or USDC in circulation, the issuer is supposed to hold $1 (or equivalent in cash, Treasury bills, money market fund shares, etc.) in segregated reserves. Authorized participants — typically institutional traders and market makers — can mint new stablecoins by sending $1 to the issuer, or redeem stablecoins for $1 each.

This redemption right creates the arbitrage loop that holds the peg:

• If USDC is trading at $0.995 on the open market, an arbitrageur buys it at $0.995, redeems with Circle for $1.00, and pockets $0.005 risk-free per coin. This buying pushes the market price back up toward $1.

• If USDC is trading at $1.005, an arbitrageur sends Circle $1.00, mints a new USDC, sells it for $1.005, and pockets $0.005. This selling pushes the market price back down.

The peg is not magic. It is held in place by people who make money every time the price drifts away from $1. As long as redemption is reliable and reserves are real, the peg is reliable. When redemption breaks down — as during the USDC depeg of March 11, 2023 — even well-managed stablecoins can briefly trade far from $1.

Risks to Be Aware Of

Stablecoins are not risk-free. The label "stable" describes the target, not a guarantee.

Counterparty and reserve risk: If the issuer mismanages reserves, lies about them, or becomes insolvent, the token can lose its peg permanently. The most famous case: in October 2021, the CFTC fined Tether $41 million after finding that, between June 2016 and February 2019, only 27.6% of days had USDT fully backed as Tether claimed. Tether's reserves and disclosures have improved substantially since, but the case is a reminder that audited financials matter.

Banking concentration risk: On March 11, 2023, Circle disclosed that $3.3 billion of USDC reserves (about 8% of $40B total) were stuck at Silicon Valley Bank when the FDIC seized the bank. USDC briefly fell to $0.87 before recovering after the FDIC announced full deposit guarantees. The lesson: even a fully backed stablecoin is only as liquid as the banks holding its cash.

Regulatory risk: This was the biggest story of 2025. The GENIUS Act (Guiding and Establishing National Innovation for U.S. Stablecoins Act) became the first federal U.S. stablecoin framework. The Senate passed it 68-30 on June 17, 2025. The House passed it on July 17, 2025. President Trump signed it into law on July 18, 2025. It requires payment stablecoin issuers to hold 100% reserve backing in cash and short-duration Treasuries, publish monthly disclosures, and comply with AML rules. In the EU, the MiCA regulation's stablecoin rules (ARTs/EMTs) took effect June 30, 2024, with broader CASP rules following on December 30, 2024. After MiCA, Tether was effectively delisted from EU-regulated exchanges, while USDC and Circle's euro stablecoin EURC dominate European on-chain dollar (and euro) flows.

Smart contract risk (for crypto-backed and synthetic stablecoins): Bugs in the underlying code can be catastrophic. Sky's USDS depends on a complex protocol; Ethena's USDe depends on perpetual futures hedging working in extreme market conditions.

Centralization and freeze risk: Both Tether and Circle have frozen addresses at law-enforcement request, including OFAC-sanctioned wallets and post-hack thief addresses. This is a feature for compliance, but it means stablecoins are not censorship-resistant the way Bitcoin or Monero are.

Practical Tips for Using Stablecoins

If you plan to hold or transact with stablecoins, here are the principles that matter most:

Diversify across issuers: Holding only one stablecoin concentrates your risk in one company, one set of banks, one regulator, and one set of smart contracts. Spreading across USDC, USDT, and USDS reduces single-point-of-failure exposure.

Read the attestations: Circle publishes monthly Deloitte attestations covering USDC reserves. Tether publishes quarterly BDO attestations. These are not full audits — an attestation confirms the assets exist on a given date — but they are vastly better than nothing. If a stablecoin issuer publishes no attestations or audits, treat that as a major red flag.

Choose your chain carefully: USDT on Tron is fast and cheap (often under $1 per transfer), but Tron is more centralized than Ethereum. USDC on Solana settles in seconds for fractions of a cent. Use the chain that matches your use case, and confirm that the recipient's wallet supports the same chain — sending USDC on the wrong network can result in lost funds.

Self-custody for amounts that matter: A stablecoin sitting on an exchange is an IOU from the exchange, not a stablecoin you control. Withdraw to a wallet you control (hardware or well-reviewed software) for anything beyond active trading capital. Remember the FTX lesson.

Be skeptical of high-yield offers: Stablecoins themselves earn no native yield. If a platform offers 12% APY on USDC with "no risk," they are taking risk somewhere — typically lending to undisclosed counterparties, running leverage, or operating a Ponzi. Anchor (the Terra ecosystem yield protocol that paid 19.5% on UST) is the textbook example of how this ends.

For Deeper Reading

Authoritative data and primary sources:

• DefiLlama Stablecoins Dashboard: https://defillama.com/stablecoins (live market caps and chain breakdowns)

• Circle Transparency: https://www.circle.com/transparency (monthly Deloitte attestations)

• Tether Transparency Report: https://tether.io/news (quarterly BDO attestations)

• CFTC v. Tether 2021 Settlement: https://www.cftc.gov/PressRoom/PressReleases/8450-21

• White House GENIUS Act Fact Sheet: https://www.whitehouse.gov/fact-sheets/2025/07/fact-sheet-president-donald-j-trump-signs-genius-act-into-law/

• ESMA on MiCA: https://www.esma.europa.eu/esmas-activities/digital-finance-and-innovation/markets-crypto-assets-regulation-mica

• World Bank Migration & Remittances 2024: https://www.worldbank.org/en/news/press-release/2024/06/26

• Artemis Analytics (stablecoin payment volume data): https://artemisanalytics.com

• Harvard Law Forum, "Anatomy of a Run: The Terra Luna Crash": https://corpgov.law.harvard.edu/2023/05/22/anatomy-of-a-run-the-terra-luna-crash/