Tether’s stablecoin supremacy under threat as USDC closes the gap after market cap explosion

A quiet shift is underway in the stablecoin hierarchy. While Tether’s USDT still dominates the digital dollar market, the gap between the two largest issuers is narrowing as USDC steadily expands its footprint and Tether’s growth shows signs of softening.

Additionally, USDC is gaining ground in the places where the next wave of crypto money is likely to show up most clearly: regulated payments, institutional settlement, and high-velocity on-chain transfers.

Tether’s USDT still holds the largest stock of digital dollars in circulation, but the contest is shifting from a simple market-cap race to a fight over which issuer controls the rails that move new capital through crypto.

That split is now visible in both the long-term structure and the last month of market-cap movement. The stablecoin market stands at about $315 billion, giving the sector a much larger base than earlier in the cycle.

Within that pool, USDT still leads with 58% market share by supply, keeping Tether firmly in command of the largest crypto cash reserve.

Supply, however, is only one part of the picture. The more revealing question is where fresh dollars are going, which token they move through, and which issuer is building infrastructure institutions can use at scale.

That is where Circle has started to build a stronger case. Circle's financial statements confirm USDC circulation reached $75 billion at the end of 2025, up 72% year over year, while Q4 on-chain transaction volume climbed to $12 trillion, up 247% from a year earlier. Those figures indicate a stablecoin moving through wallets, venues, and payment flows more quickly.

Tether, for its part, remains too large to dismiss. In its latest quarterly disclosure, Tether stated USDT circulation topped $186 billion, reserve assets approached $193 billion, and its total US Treasury exposure reached $141 billion.

It also said it issued nearly $50 billion in new USDT during 2025. Those figures show a business that still dominates the inventory side of crypto dollars, especially across exchanges, offshore trading venues, and markets where users want a dollar-linked asset without relying on local banking systems.

Over the past month, USDC’s market cap has risen around 8%, pushing it to roughly $79 billion and a fresh all-time high.

Tether has remained far larger, but USDT is still sitting about $3 billion below the roughly $187 billion peak it reached in December 2025, a gap that gives Circle a clearer opening to chip away at Tether’s lead than the headline supply table alone suggests.

So the tension is real. Tether still controls the biggest pile of crypto cash. Circle is building faster in the parts of the market most closely aligned with the next phase of regulation and institutional adoption.

For traders and Bitcoin investors, stablecoins remain the main form of dollar liquidity inside crypto.

Whoever captures more of the next inflow can shape where liquidity thickens, how collateral is posted, and which rails become the default path for new capital entering the market.

USDT still owns supply, while USDC is winning more of the flow

The cleanest way to understand the shift is to separate supply from velocity. USDT still leads in outstanding supply, meaning more dollars are parked in Tether than in any rival stablecoin. But transaction data suggests USDC is gaining influence over how money moves.

Bloomberg, citing Artemis Analytics, reported that stablecoin transaction volume rose 72% to $33 trillion in 2025, with USDC accounting for $18.3 trillion and USDT for $13.3 trillion.

That divergence carries more weight than a simple supply table. A stablecoin that wins more transaction flow can become the preferred medium for settlement, treasury movement, and short-duration capital rotation, even while another token still holds a larger long-term balance.

Put differently, Tether still looks stronger as stored crypto cash, while Circle is making a case to become the preferred token for moving crypto cash.

The market is also assigning the two issuers different jobs. Tether’s edge remains distribution. It has the deepest footprint across global exchanges and a large user base in emerging markets, where demand for dollar-linked assets often reflects local currency weakness, capital controls, or banking friction.

Circle’s edge is legibility. It has built a reserve model and disclosure framework that fit more naturally with banks, regulated payment firms, and institutions that need cleaner lines around custody, compliance, and audits.

Circle’s own transparency page makes that pitch directly. The company says the bulk of USDC reserves sit in the BlackRock-managed Circle Reserve Fund, with the rest primarily in cash at regulated financial institutions, and notes that its financial statements are audited by Deloitte.

That does not erase market competition, and it does not guarantee that USDC will overtake USDT by supply. It does give Circle a stronger position in the regulated lane of the market at a moment when regulation is beginning to sort winners by use case.

The policy backdrop is moving in that direction. A Federal Reserve Bank of St. Louis review of the GENIUS Act framework says payment stablecoin issuers face tight reserve rules, monthly disclosures, and annual audited financial statements once issuance passes $50 billion.

State-qualified issuers above $10 billion would also need to move toward federal oversight within a year. Those thresholds do not decide the market on their own, but they make compliance architecture more important than it was during the earlier, more crypto-native phase of stablecoin growth.

That split is already visible in payments. Visa launched USDC settlement in the United States with Cross River Bank and Lead Bank and plans broader U.S. expansion through 2026. It also said its monthly stablecoin settlement volume had reached a $3.5 billion annualized run rate as of November 30.

That is not the same as saying USDC will dominate all crypto activity. Circle, however, is gaining share in one of the most important growth lanes outside exchange trading.

The Bitcoin implication centers on liquidity, collateral, and who captures the next inflow

For Bitcoin, the stablecoin contest is not a side issue. Stablecoins fund exchange balances, back collateral positions, and give traders a dollar-linked unit that can move around the clock without leaving the crypto system.

When stablecoin supply grows, the market’s pool of deployable dollar liquidity tends to deepen. When one stablecoin gains more of that growth, the question becomes which venues and user groups will control the new liquidity.

Glassnode has described the Stablecoin Supply Ratio as a gauge of stablecoin-denominated buying power relative to Bitcoin supply, with lower readings implying greater potential purchasing power. That supports a practical point: stablecoins are one of the clearest ways to measure how much dollar liquidity is sitting inside crypto and how ready that liquidity may be to rotate into BTC.

If USDT remains the main store of offshore trading cash while USDC gains ground in regulated settlement and enterprise finance, Bitcoin liquidity could become more segmented over the next year. Offshore spot and derivatives venues may remain heavily USDT-centric.

Meanwhile, institutionally mediated Bitcoin activity could lean more toward USDC as banks, payment firms, and treasury desks choose the stablecoin that best fits compliance, reserve transparency, and settlement requirements.

That would not weaken Bitcoin. Tether would still matter most for the largest reservoir of crypto-native trading capital, and it could broaden the set of rails that feed Bitcoin demand.

Circle would matter more for the next tranche of regulated capital seeking a stablecoin bridge to digital assets without stepping outside traditional financial guardrails.

Standard Chartered has projected that the stablecoin market could reach $2 trillion by the end of 2028. From a base of roughly $315 billion today, that implies about $1.7 trillion of additional room for growth.

The key question is which issuer, reserve model, and regulatory framework will capture the next $1.7 trillion.

There are several plausible paths from here.

• USDT keeps the largest share of outstanding supply because its exchange and international distribution remain hard to replace, while USDC continues to gain in institutional payments and regulated settlement.
• Policy clarity and more bank integrations allow USDC’s lead in transaction velocity to translate into much bigger gains in outstanding supply.
• The market keeps assigning USDT the role of dominant crypto trading cash, and USDC’s gains remain meaningful but narrower, concentrated in regulated channels rather than across the full market.

The evidence today supports the first path more than the others. Tether is still too large, too embedded, and too useful across crypto’s global trading stack to call this an imminent overthrow.

Circle, though, has enough momentum in transactions, reserve design, and institutional integrations to argue that the next phase of stablecoin growth may not belong to the same issuer that dominated the last one.

Circle’s case also rests on recency, not just structure. USDC has hit a new market-cap high near $79 billion after roughly 8% monthly growth, while USDT has yet to reclaim the peak it reached in December 2025.

The broader takeaway for Bitcoin and the wider market is straightforward. USDT still owns the largest share of crypto’s cash inventory. USDC is making a stronger claim on crypto’s future cash plumbing.

If stablecoins are heading toward a multi-trillion-dollar market, the fight is no longer just about who is biggest now. It is about who captures the next wave of money, and which version of the dollar becomes the preferred bridge into Bitcoin, exchanges, payments, and on-chain finance.

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