# The Stablecoin Siege: USDT vs USDC in Asia's $1.2T Settlement Layer

*ium Research — David, CEO — May 8, 2026*
*Canonical: https://iumlabs.io/blog/the-stablecoin-siege-usdt-vs-usdc-in-asia*

## Key Takeaways

- USDT's circulating supply sits near 186.4 billion dollars versus USDC's 74.8 billion, a roughly two-and-a-half-to-one lead that defines the incumbency gap. (Source: DefiLlama, Stablecoin dashboard)
- USDT processed roughly 703 billion dollars per month between June 2024 and June 2025, peaking at 1.01 trillion dollars in June 2025 in on-chain settlement volume. (Source: Chainalysis, 2025 Global Adoption Index)
- APAC was the fastest-growing region for on-chain crypto activity, up 69 percent year over year to 2.36 trillion dollars in value received. (Source: Chainalysis, 2025 Global Adoption Index)
- South Korea ranked as the world's second-largest fiat on-ramp at over 722 billion dollars, behind only the United States. (Source: Chainalysis, 2025 Global Adoption Index)

Asia's dollar-settlement layer is not a technology contest. The chains are commoditized, the pegs hold, and a transfer clears in seconds either way. What separates the two dominant dollar tokens is distribution and regulation. USDT owns the retail and OTC plumbing across Asian markets through sheer liquidity and incumbency. USDC is building the opposite wedge: compliance, banking relationships, and an institutional posture that regulators can underwrite. For operators bringing a token or a product into Korea, this split is the map. And it intersects with a live local question: whether a regulated won-stablecoin rail could reroute the flow that currently runs on someone else's dollar.

The instinct is to pick a winner. That is the wrong frame. These two tokens are not competing for the same buyer; they are optimized for opposite ends of the same market. Reading their numbers side by side makes the division of labor obvious, and once it is obvious, the operator decision stops being "which one" and becomes "which one where."

## 1. The Two Dollars, By the Numbers

The headline gap is supply. USDT and USDC together dwarf every other stablecoin, but they are not close to each other.

*[Figure: DefiLlama, stablecoin dashboard showing total market cap and USDT dominance near 59 percent]*

| Item | Value |
|---|---|
| USDT (Tether) | 186.4 |
| USDC (Circle) | 74.8 |
| USDS (Sky) | 8.2 |
| USDe (Ethena) | 4.5 |

*Stablecoin circulating supply in billions of dollars. USDT leads USDC by roughly 2.5 to 1. Source: DefiLlama, Stablecoin dashboard, June 2026*

Supply understates USDT's lead in movement. On-chain settlement volume tells the real story of which token is doing the work.

> **1.01 trillion** — USDT monthly on-chain settlement volume, peak in June 2025 (Source: Chainalysis, 2025 Global Adoption Index)

USDC's volume over the same period was far more volatile, and its supply spent 2025 on what one analysis called a roller-coaster, recovering to a 73.4 billion dollar market cap by mid-year after a January low near 53.3 billion. USDT is the default unit of account for Asian crypto liquidity. USDC is the regulated alternative trying to win on terms USDT cannot easily match.

Laid out against each other, the two tokens are not racing on one axis. They are winning on different ones.

| Dimension | USDT (Tether) | USDC (Circle) |
|---|---|---|
| Circulating supply | 186.4 billion dollars | 74.8 billion dollars |
| Supply trajectory in 2025 | Steady incumbent leader | Roller-coaster; low near 53.3B in January, ~73.4B by mid-year |
| Settlement volume | Peaked at 1.01 trillion dollars monthly (June 2025) | Far more volatile over the same period |
| Primary moat | Liquidity, P2P depth, OTC incumbency | Compliance, banking partners, regulatory acceptance |
| Asia stronghold | Retail and OTC flow; trades at a P2P premium | Licensed exchanges, payment processors, fintechs, tokenization |
| Regulatory posture | Lighter posture, broad reach | Built around frameworks like the US GENIUS Act |

This is the core of the siege: not one token displacing the other, but two distribution strategies dividing the continent's flow between reach and auditability.

## 2. Why USDT Leads Asia

USDT's lead in Asia is a distribution moat, not a product advantage. It was first, it is everywhere, and liquidity compounds. Across most emerging markets USDT commands higher peer-to-peer rates than USDC because of its larger market share and deeper order books, which means the incumbent literally trades at a premium. That premium is the moat made visible.

> Embedded post: https://twitter.com/Cointelegraph/status/2002242649655271873

> Embedded post: https://twitter.com/beincrypto/status/2001574775945376129

*[Figure: Tether, new USDT on-chain wallets and accounts per quarter rising through 2024]*

The mechanism is reflexive, which is why it is so hard to dislodge. Depth attracts traders, traders deepen the book, and the deeper book lets USDT clear large OTC tickets at tighter spreads than any challenger. A market maker who can settle a block in USDT without moving the price has no reason to hold USDC, and an OTC desk that quotes the tightest USDT spread becomes the desk everyone routes through. The premium and the depth feed each other, and the result is an incumbency that compounds quarter over quarter rather than decaying.

The more important shift is what USDT is used for. It has quietly become a payments rail, not just a trading instrument.

> **"USDT is increasingly acting as a substitute for cash and bank wires in regions where access to dollars is limited or expensive."**
>, Mohammad Shahid, BeInCrypto

The numbers back the framing. Tether, whose reserve composition is published through its [official attestations](https://tether.to/en/transparency/), disclosed that USDT processed roughly 156 billion dollars in payments of 1,000 dollars or less during 2025, with average daily volumes for sub-1,000-dollar transfers climbing above 500 million dollars. These are remittances, payroll, and retail transfers, the non-speculative flows that make a settlement layer sticky. In Asia, where USD access through banks is uneven and OTC desks are dense, that stickiness is USDT's defining asset.

> **156 billion** — USDT processed in sub-1,000-dollar payments during 2025, the remittance and retail flow that makes the rail sticky (Source: Tether)

> Embedded video: https://www.youtube.com/watch?v=IAChB5ls6eU

## 3. USDC's Compliance Wedge

USDC cannot out-liquidity USDT in Asian retail. So Circle, which publishes [monthly USDC reserve attestations](https://www.circle.com/transparency), is fighting on a different axis: regulation. The passage of the GENIUS Act in the United States, the first federal framework for payment stablecoins, drove strong institutional interest toward compliant dollar-backed tokens even before the rules took full effect.

> Embedded video: https://www.youtube.com/watch?v=996EUIoAqms

*[Figure: Source: Chainalysis, 2025 Global Adoption Index, "Stablecoins surge globally for a variety of use cases"]*

This is the wedge. USDC's growth is closely linked to US-based institutional rails and regulated corridors, while incumbents dominate the unregulated retail flow. Where USDT optimizes for reach, USDC optimizes for auditability, banking partners, and regulatory acceptance. In Asia that means a specific play: payment processors, licensed exchanges, fintechs, and tokenization platforms that need a stablecoin a compliance officer can sign off on. Visa, Mastercard, Stripe, and Citi are all building stablecoin settlement into traditional rails, and that institutional layer is the corridor USDC is built to win. It does not beat USDT on volume; it carves out the regulated segment USDT's lighter posture has more trouble serving.

The strategic logic is that the regulated segment is the one that grows when the rules arrive. A compliance officer cannot route corporate treasury through a rail they cannot underwrite, so as more jurisdictions write stablecoin law, the audit-ready token inherits flows that were previously stuck on bank wires. USDC is not trying to convert the OTC trader who already loves USDT; it is positioning for the payment processor and the licensed venue whose entire reason for existing is that a regulator signed off. That is a smaller pool today and a structurally expanding one, which is the bet Circle is making.

## What This Means for Operators

If you are launching a token or a product into Asia, the dollar layer is a routing decision, not a default. Retail liquidity, P2P depth, and OTC settlement run on USDT, so depth and listings follow it. Institutional, compliance-bound, and payments flows increasingly route through USDC, where banking partners and regulated venues sit. Picking one settlement asset commits you to its distribution and its regulatory profile. The smarter posture is corridor-by-corridor: USDT where you need reach, USDC where you need a counterparty who answers to a regulator. Korea sharpens this. Ranked the second-largest fiat on-ramp globally at over 722 billion dollars, its dollar flow is enormous, and where that settles after on-ramp is the question a go-to-market plan has to answer.

In practice that on-ramp question is inseparable from the venue question, because in Korea the fiat gateway is the exchange itself. Where the won converts to a dollar token, and which token, is gated by the same real-name, exchange-bound rails that keep Korean activity centralized in the first place, a structure we unpack in [Korea's DeFi paradox](/blog/korea-defi-paradox-why-active-traders-wont-touch-onchain).

## What Breaks It

The two-horse frame breaks if a regulated local rail captures the flow. In Korea, a won-stablecoin is exactly that threat. The legislation has stalled on a real divide: whether stablecoins are classified as currency or as digital assets, and whether issuance is limited to banks or open to private firms. Non-bank proposals require at least 5 billion won in capital and 100 percent reserves under the Financial Services Commission; the bank-based proposal treats stablecoins as part of the national currency system under the Bank of Korea and the finance ministry.

> **5 billion won** — Minimum capital proposed for non-bank KRW stablecoin issuers in Korea (Source: Tiger Research, 2025 KRW Stablecoins Status)

The market is not waiting. The BDACS-Woori Bank consortium has already deployed a won stablecoin, KRW1, on Avalanche and is testing on Circle's ARC network, while Naver Pay and Dunamu explore their own rail. A credible regulated won token would not kill USDT or USDC, but it could reroute domestic settlement onto a rail Korean regulators control, shrinking the dollar-stablecoin footprint inside the country's borders. That is the scenario operators should price in. The full legislative picture, including how the won-stablecoin debate folds into Korea's broader digital asset framework, is covered in [the Korean won stablecoin and Digital Asset Basic Act](/blog/korea-won-stablecoin-digital-asset-basic-act-2026).

## How We Run It

ium Labs treats the stablecoin question as a distribution problem, because that is what it is. For a project entering Korea we map which corridors your users actually settle in, match the dollar rail to the venue and the compliance posture, and sequence listings, OTC relationships, and payment integrations against the live regulatory timeline. When the won-stablecoin framework lands, the projects positioned across both the dollar rails and the emerging local rail will move first. That is the work: turning a two-horse settlement market into a routing strategy your launch can execute on.

See how we structure market entry at [/services/gtm](/services/gtm), or talk to us directly at [/contact](/contact).

## Sources

- [DefiLlama, Stablecoin Market Cap, Supply and Peg Data](https://defillama.com/stablecoins)
- [Chainalysis, The 2025 Global Adoption Index](https://www.chainalysis.com/blog/2025-global-crypto-adoption-index/)
- [BeInCrypto via Yahoo Finance, Tether's USDT Payment Stats Show the Real State of Crypto Adoption in 2025](https://finance.yahoo.com/news/tether-usdt-payment-stats-show-030000584.html)
- [Tiger Research, 2025 KRW Stablecoins Status](https://reports.tiger-research.com/p/korea-stable-coin-eng)
- [Crystal Intelligence, USDT maintains dominance while USDC faces headwinds](https://crystalintelligence.com/thought-leadership/usdt-maintains-dominance-while-usdc-faces-headwinds/)
- [Law.asia, Guide to Korea's Stablecoin Regulation Framework](https://law.asia/korea-stablecoin-regulation-framework/)
- [CNBC International, How Stablecoins Took Over Asia](https://www.youtube.com/watch?v=IAChB5ls6eU)
- [Tether, How Many USDT Users Are There](https://tether.io/news/how-many-usdt-users-are-there/)
- [YouTube, Different Stablecoins Which Should You Choose and Why](https://www.youtube.com/watch?v=996EUIoAqms)

*This report reflects ium Labs' operating view and is intended for general information, not investment advice.*