Canonical: https://builtonarc.app/guides/stablecoin-chains-compared-2026
# Stablecoin chains compared, 2026: who's live, who isn't, and whether the market is big enough for all of them
Updated 2026-09-02. Arc, Tempo, Codex and Plasma compared, 2 Sep 2026 — what's live, what's pre-mainnet, and whether real payment volume supports this many chains.
> As of 2 September 2026, "purpose-built stablecoin chain" describes a real, fast-growing category with at least four serious entrants — Arc, Tempo, Codex, and Plasma — but they aren't four versions of the same thing. Tempo and Plasma are live Layer 1s. Arc is a Layer 1 two weeks from mainnet. Codex isn't a Layer 1 at all — it's a payments infrastructure company that settles across other chains. And the category as a whole is being built for a real-economy stablecoin payments market — $350–550 billion a year — that's a fraction of the $46 trillion headline volume the sector likes to cite. This guide doesn't rank the four; it lays out what each one actually is, and names the thesis-level risk plainly: several chains are chasing a market that may not be large enough to support all of them.
## The category, defined narrowly
A "purpose-built stablecoin chain" here means a Layer 1 designed from the base layer up around stablecoin settlement — native or near-native stablecoin gas, a payments-first fee model, and a validator design chosen with payments counterparties in mind. That excludes general-purpose L1s that happen to carry stablecoin volume (Tron, Solana, Ethereum) and Ethereum L2s carrying stablecoins on top of a chain not designed around them (Base, Arbitrum, Optimism) — both get their own comparisons elsewhere in this cluster. This guide covers only the chains built for this one job first.
## What's actually live vs. what's a date on a calendar
Get this straight before anything else, because it's the single most load-bearing fact in this category: **Tempo and Plasma are live. Arc is not, yet. Codex is live but isn't a chain.**
Tempo went mainnet 18 March 2026, after a public testnet that began in December 2025 — a payments-focused Layer 1 backed by Stripe and Paradigm, with a $500 million Series A closed October 2025 at a $5 billion valuation ([The Block](https://www.theblock.co/post/402043/moneygram-remittance-validator-stripe-tempo-blockchain)). It's been in production for over five months as of this writing.
Plasma's mainnet beta launched with a reported $2 billion in liquidity committed on day one — Plasma's own public materials don't state an exact date, but the token's all-time high is dated 27 September 2025 on CoinGecko, which places the launch around that period ([CoinGecko](https://www.coingecko.com/en/coins/plasma)).
Arc's public testnet has run since 28 October 2025. Mainnet is scheduled for 16 September 2026 — two weeks after this guide's publish date. Circle states more than 100 ecosystem and institutional builders are active on a private mainnet already, but nothing about Arc's live fee behavior, validator conduct, or throughput is verifiable in public before the mainnet date.
Codex — covered in its own dedicated comparison because the "is it a chain" question is load-bearing enough to need one — is a live, operational stablecoin FX and payments company reporting over $1 billion a month in volume, but it settles across existing chains (including Ethereum, Solana, and Tron) rather than running its own Layer 1. It belongs in this roundup because builders search for it alongside the other three, not because it competes with them on chain-level terms.
No other purpose-built stablecoin Layer 1 with a comparably verifiable public record was confirmed during research for this guide as of 2 September 2026 — that space may fill in further as the category matures, but this guide isn't going to name a chain it couldn't verify.
## The comparison, axis by axis
**Execution and tooling.** Tempo, Plasma, and Arc are all EVM-compatible — Solidity and standard EVM tooling apply on all three, which flattens the switching-cost differences between them relative to, say, an SVM chain. Codex doesn't have its own execution environment; it settles through whichever chain a transaction ultimately touches.
**Fee model.** This is where the four diverge most. Arc's gas is USDC-denominated natively at the protocol level. Tempo's TIP-20 token standard lets fees be paid in any supported stablecoin via a built-in fee-conversion AMM, and Tempo publishes an average fee under $0.001 for standard stablecoin transfers (its own benchmark, not independently audited). Plasma's signature feature is zero-fee USDT transfers on its own routes, subsidized at the protocol level, with XPL as the native token for everything outside that lane. Codex, as an infrastructure layer rather than a chain, doesn't have a native gas model at all — its economics are a service fee on FX conversion and settlement routing, a different kind of cost entirely.
**Finality and throughput.** Arc targets roughly 780ms finality via Malachite (a Tendermint-based BFT engine) across a permissioned validator set of about 100 institutions; no mainnet throughput figure is published yet. Tempo publishes a self-reported 508ms average time between finalized blocks and a claimed 21,200 settled transfers per second. Plasma runs its own consensus, PlasmaBFT, with finality and throughput figures not detailed in the documentation reviewed. None of these numbers are directly comparable without knowing each vendor's test conditions — Tempo's come from production benchmarks, Arc's from a pre-mainnet target — and shouldn't be placed side by side as if measured the same way.
**Validator model and compliance posture.** Arc's cohort is the most institutionally concentrated: eleven named founding validators — BlackRock, DTCC, Galaxy, Global Payments, ICE, Mastercard, MoneyGram, SBI Group, Standard Chartered, Sumitomo Corporation, and Visa — disclosed by Circle on 5 August 2026. Tempo's reported initial corporate validators include Stripe, Visa, Zodia Custody (being absorbed into Standard Chartered), and MoneyGram, with Mastercard, UBS, and Kalshi as testnet design partners — smaller, concentrated toward Tempo's own commercial backers. Plasma's validator composition — permissioned or not, how many are active — isn't detailed in the public documentation reviewed; not yet confirmed. Codex has no validator set of its own, since it isn't a chain.
**Notice how many names repeat.** Mastercard is an Arc founding validator and a Tempo testnet design partner. MoneyGram is an Arc founding validator and Tempo's reported "Anchor Remittance Validator." Visa is an Arc founding validator and a Tempo ecosystem partner, and separately settles USDC on Solana. Read that pattern plainly: payments incumbents are hedging across competing stablecoin chains rather than picking a winner — a more honest signal than any one chain's own marketing.
**Stablecoin issuer relationship.** Arc's is the most direct of the four: Circle, the issuer of USDC, operates the network itself. Tempo doesn't have a comparable single-issuer relationship — its TIP-20 model is designed to be stablecoin-agnostic rather than built around one issuer. Plasma's zero-fee lane is specifically built around USDT, Tether's stablecoin, though Tether doesn't operate Plasma's validator set. Codex, as infrastructure rather than a chain, moves USDC, USDT, and PYUSD across the chains it settles through, without an issuer relationship of its own.
## The market-size question this category can't avoid
Total stablecoin supply sits around $308 billion as of 13 August 2026 — up 14% year over year, but 4.5% below the May 2026 peak, effectively flat for months ([DeFiLlama](https://defillama.com/stablecoins)). The headline figure the sector quotes — roughly $46 trillion in annual stablecoin transaction volume — is dominated by trading and internal transfers, not commerce. Real-economy payments volume is closer to $350–550 billion a year, with B2B volume around $226 billion a year. Only about 13% of organizations report having used stablecoins, though 87% call it a competitive advantage — a wide gap between interest and usage.
Put plainly: at least four purpose-built chains — plus Codex, plus every general-purpose chain and L2 also chasing this volume — are building for a real-economy market that is, today, one to two orders of magnitude smaller than the headline trading-volume figure the category advertises. That's not a reason to dismiss the category — 87% calling stablecoins a competitive advantage suggests real latent demand — but it is the honest thesis-level risk under every comparison in this cluster: several chains are building for the same still-developing volume, and at least one will not find enough of it to justify the commitments already made. Built on Arc doesn't predict which one; the math doesn't currently support all of them succeeding at the scale their backers are pricing in.
## Which fits which job
None of this is a ranking, and the four don't reduce to one "best" answer. A builder whose product is USDT-heavy and needs a live chain today has Plasma's zero-fee lane. One who needs live merchant distribution now has Tempo. One who wants to abstract chain choice away entirely has Codex. One who specifically needs the USDC issuer operating the base layer and a named institutional validator cohort has a case to wait two weeks for Arc — recognizing "wait" is a real cost against three competitors already live. See Arc vs Tempo, Arc vs Codex, and Arc vs Plasma for the detail behind each call.
Built on Arc is an independent directory. Arc is a Circle product; we are not affiliated with, endorsed by, or operated by Circle.
Sources:
- [Circle Announces Founding Validator Cohort and Major Integrations for Arc](https://www.circle.com/pressroom/circle-announces-founding-validator-cohort-and-major-integrations-for-arc-ahead-of-september-16-mainnet-launch)
- [The Block: MoneyGram named 'anchor remittance validator' for Tempo](https://www.theblock.co/post/402043/moneygram-remittance-validator-stripe-tempo-blockchain)
- [The Block: RedStone oracle provider integrates with Tempo mainnet](https://www.theblock.co/post/394103/stripe-paradigms-tempo-blockchain-redstone-data-oracle)
- [Tempo — official site](https://tempo.xyz)
- [Codex — official site](https://www.codex.xyz)
- [Plasma — official site](https://www.plasma.org)
- [CoinGecko: Plasma (XPL)](https://www.coingecko.com/en/coins/plasma)
- [DeFiLlama: stablecoin market cap](https://defillama.com/stablecoins)
## Questions
**Which stablecoin chains are actually live right now?**
Tempo (mainnet since 18 March 2026) and Plasma (mainnet beta, launched with a reported $2 billion in day-one liquidity) are both live. Arc is pre-mainnet until 16 September 2026. Codex is live but isn't a Layer 1 — it's payments infrastructure that settles across other chains.
**Is Codex a competitor to Arc, Tempo and Plasma?**
Not directly — it operates at a different layer of the stack, routing payments across existing chains rather than running its own validator set and consensus. See Built on Arc's dedicated Arc vs Codex guide for the detail.
**Why do the same institutions keep appearing across multiple chains?**
Mastercard, MoneyGram, and Visa each have confirmed ties to more than one of these chains. That's evidence of payments incumbents hedging across an unproven category, not evidence that any one chain has won.
**Is the real-economy stablecoin payments market big enough for all these chains?**
Not obviously. Real-economy payment volume is estimated at $350–550 billion a year, versus a $46 trillion headline trading-volume figure the sector often cites — a market that may not support every chain currently building for it at the scale investors have priced in.
**Which chain has the deepest institutional validator cohort?**
Arc's, on current public disclosure — eleven named institutions including BlackRock, DTCC, Mastercard, and Visa. Tempo's and Plasma's validator compositions are less fully disclosed publicly as of this writing.
**Does this guide recommend one chain?**
No. Built on Arc's editorial stance is status and verification, not ranking — see the axis-by-axis breakdown above and the individual chain comparisons linked for the specifics relevant to your own product.