Stablecoins · Blockchain Infrastructure · Token economics · Financial Regulation · Settlement-Layer ComparisonArc mainnet, 16 Sep 2026 · record to 17 Sep 2026
Settlement-layer comparison · two chains, two business models
A Chain of Its Own, and the Bill It Still Pays
On 16 September 2026 Circle opened the public mainnet of Arc, a Layer 1 blockchain whose gas is paid in USDC rather than in a token that moves, secured by a permissioned validator set that includes BlackRock, DTCC, Visa, Mastercard and ICE. The obvious comparison is Base, Coinbase’s Ethereum Layer 2, which is the largest rollup there is. It is a fair comparison and it is not where the money is. Circle’s own annual report says it paid Coinbase US$1.4bn in 2025 — against US$2.75bn of total revenue and reserve income — and a chain of its own does not change a distribution agreement.
What Happened
What happened graded by how well each is established
- 16 Sep 2026Arc’s public mainnet opens, with gas paid in USDC
- 11 + Circlefounding validators, among them BlackRock, DTCC, Visa and Mastercard
- 10bnARC tokens minted at genesis in launch week — which Circle says is not a commitment to launch the token
- US$1.4bnCircle’s 2025 distribution costs under its Coinbase agreements — 51% of its revenue and reserve income
| Standing | What happened | Source |
|---|---|---|
| Confirmed | Arc’s public mainnet opened on 16 September 2026. Fees are paid in USDC with no volatile native token required; finality is deterministic and sub-second; more than 100 applications and more than 100 institutional and ecosystem builders were live on day one, on a testnet that opened in October 2025 and processed more than 700 million transactions. | Circle, 16 Sep 2026 |
| Confirmed | Eleven institutions validate alongside Circle, in a phased rollout: BlackRock, DTCC, Galaxy, ICE, Mastercard, MoneyGram, SBI Group, Standard Chartered, Sumitomo Corporation, Visa and Worldpay, now Global Payments. | Circle, 5 Aug and 16 Sep 2026 |
| Confirmed | Circle completed the genesis mint of the ARC token in launch week, creating the full initial supply of 10 billion, and calls itself the first publicly traded company to mint a network token for a new Layer 1. It states plainly that the mint is not a commitment to launch ARC publicly, that network fees remain payable in USDC, and that a move from proof of authority towards proof of stake is something the network explores in 2027. | Circle, 16 Sep 2026 |
| Confirmed | The presale that preceded it is on the record twice. On 8 May 2026 Circle agreed to sell 740 million ARC at US$0.30, raising US$222.0m and implying a US$3bn fully diluted network valuation, led by a16z crypto; on 29 and 30 June a second closing added 67.5 million tokens for US$20.25m on the same terms. Buyers are locked up for at least a year after a proof-of-stake transition, and may demand repayment if that transition has not happened by 8 May 2028. | Circle, Forms 8-K, 11 May and 2 Jul 2026 |
| Confirmed | The day before the launch, the United States Senate rejected cloture on the motion to proceed to H.R. 3633, the Digital Asset Market CLARITY Act, by 49 votes to 50 — eleven short of the sixty needed, and one short of a simple majority. | US Senate roll call 234, 15 Sep 2026 |
| Confirmed | On the launch day itself the Federal Open Market Committee voted 12–0 to raise the federal funds target range by a quarter point, to 3-3/4 to 4 percent, saying inflation remains elevated. Circle’s revenue is almost entirely interest on reserves, so the move runs in its favour. | Federal Reserve, 16 Sep 2026 |
| Confirmed | CRCL closed at 86.30 on 15 September, down 11.41%, and at 80.45 on 16 September, down a further 6.78%. COIN closed at 172.11 and then 164.51. Bitcoin fell 3.26% across the first of those two sessions. The equity move was several times the crypto move. | Yahoo Finance chart data, read 17 Sep 2026 |
| Confirmed, not verifiable here | Circle’s agreement with Coinbase is reported to roll forward on unchanged terms into 2029, from what its chief executive said on the 5 August earnings call. The filings describe a three-year term renewing automatically unless a party fails its obligations, but name no date, and the call was not read here. | Circle Form 10-K, 9 Mar 2026; the 2029 date from reporting of the call |
| Not established | What Open USD does to USDC. The consortium token was unveiled on 30 June 2026 with more than 140 partners, Coinbase among them, and is described as launching later in 2026. It is not live, its chains are reported inconsistently, and no effect on USDC’s circulation can yet be measured. | Crypto Briefing, 30 Jun 2026; crypto.news, 1 Jul 2026 |
| Not established | Whether ARC ever trades, and whether Arc’s opt-in privacy ships. Circle describes the privacy design as in development for network-wide release, and the token mint as a technical milestone rather than a commitment. | Circle, 16 Sep 2026 |
Timeline
In what order only dated, documented events
- 5 Jun 2025Circle lists on the New York Stock Exchange at US$31.00 a share, selling 19.9 million Class A shares for net proceeds to the company of US$583.0m. The first close is 83.23, up 168.5% on the offer price.
- 18 Jul 2025The GENIUS Act becomes Public Law 119-27. It forbids a permitted stablecoin issuer from paying a holder any interest or yield for holding the token. It says nothing about a distributor.
- Oct 2025Arc’s public testnet opens. It will process more than 700 million transactions in under a year.
- 31 Dec 2025USDC in circulation reaches US$75.3bn, up 72% on the year, while the reserve return rate falls from 5.0% to 4.1%. USDC held on Coinbase’s own platform rises from US$2,236m to US$12,503m.
- 18 Feb 2026Base says it is consolidating onto a Base-managed codebase and stepping back from Optimism’s OP Stack, aiming to roughly double its pace of major upgrades. OP Labs says it will keep serving Base as an enterprise customer.
- 9 Mar 2026Circle’s annual report puts 2025 distribution costs under its Coinbase agreements at US$1.4bn, against US$924.5m in 2024. Total revenue and reserve income for the year is US$2,746.6m; the company reports a loss from continuing operations of US$70m.
- 8 May 2026The ARC presale: 740 million tokens at US$0.30, US$222.0m raised, a US$3bn fully diluted network valuation, led by a16z crypto.
- 29–30 Jun 2026A second closing adds 67.5 million ARC for US$20.25m on the same terms.
- 30 Jun 2026Open Standard unveils Open USD, a consortium stablecoin with more than 140 partners including Coinbase, Visa, Mastercard, BlackRock and Stripe, which would return reserve earnings to partners after a management fee. CRCL closes at 62.63, down 17.55% on the session.
- 5 Aug 2026Circle reports its second quarter: reserve income of US$668m out of US$702m of revenue, net income of US$48m, and US$324.6m paid to Coinbase in the quarter alone. The same day it names Arc’s eleven founding validators and the 16 September date.
- 15 Sep 2026Senate cloture on the motion to proceed to the CLARITY Act fails 49–50. CRCL falls 11.41% and COIN 10.10%; bitcoin falls 3.26%.
- 16 Sep 2026Arc’s public mainnet opens. Hours earlier the Federal Open Market Committee raises the federal funds target range by a quarter point to 3-3/4 to 4 percent. CRCL closes down a further 6.78%, at 80.45.
- 17 Sep 2026USDC stands at US$73.84bn, 23.62% of a US$312.6bn stablecoin float, behind USDT’s 58.62%. Base secures US$14.53bn, the largest of any rollup. Arc holds US$0.33bn of value in decentralised finance on its second day.
The Argument
The argument what the filings say, and what the statute makes possible
Circle’s largest expense is a distributor, not a chain. Its annual report for 2025 states it plainly: “For the years ended December 31, 2025 and 2024, we incurred US$1.4 billion and US$924.5 million respectively, of distribution costs in connection with our agreements with Coinbase.” Against total revenue and reserve income of US$2,746.6m, the 2025 figure is 51% of everything the company earned. In the second quarter of 2026 the same line came to US$324.6m, against US$668m of reserve income in the quarter.
The reason that arrangement can exist is in the statute. The GENIUS Act forbids a permitted issuer from paying “any form of interest or yield” to a holder “solely in connection with the holding, use, or retention” of a payment stablecoin. The prohibition binds the issuer. It does not by its terms reach a distributor — and Coinbase’s own annual report lists USDC rewards among the benefits of a Coinbase One subscription, and counts holding USDC as a transaction that makes a user a monthly transacting user. So the yield on Circle’s reserves reaches the person holding the token by passing through an exchange, and the exchange prices that passage. That reading is this article’s inference from the text, not a ruling by anybody.
Arc does not touch it. A chain decides where USDC settles and what a transaction costs to order. It does not decide who puts USDC in front of a customer, and the agreement that governs that renews itself: the filing describes an initial three-year term rolling over automatically into further three-year terms unless a party fails its obligations. What would touch it is Open USD, whose published design returns reserve earnings to the partners distributing the token rather than to the issuer holding the reserve. That is the same bill, re-addressed. It is also, eleven weeks after being unveiled, still a token that does not exist.
- 51%of Circle’s 2025 revenue and reserve income went out as distribution costs under its Coinbase agreements
- US$1.35bnCoinbase’s own 2025 stablecoin revenue, which it says comes primarily from the Circle arrangement — a different measure from Circle’s US$1.4bn, and not the same number
- 48.6%of the second quarter of 2026’s reserve income was paid to Coinbase — US$324.6m of US$668m
The statute names the issuer, not the distributor
This is the load-bearing asymmetry, and it is in the enrolled text rather than in commentary. Circle may not pay a holder for holding USDC; Coinbase may, and does. Whatever else changes, that gap is what a distribution agreement is priced against.
A chain answers a different question
Arc gives Circle a settlement layer it controls, priced in its own token, with institutions inside the validator set. That is a real position and it is worth having. It is not an answer to a distribution bill, and reading the launch as one mistakes the axis the pressure is on.
And the thing that would answer it does not exist yet
Open USD is a published design, a partner list and a management fee. Until a token is live and someone has moved a balance onto it, its effect on USDC is not a small number — it is no number at all, and should not be written as one.
What Others Add
What others add the two chains side by side, from their own documentation
| Aspect | Arc | Base |
|---|---|---|
| Kind | An independent Layer 1 | A Layer 2 on Ethereum, an optimistic rollup at Stage 1 |
| Consensus and security | Malachite, an implementation of Tendermint BFT, over a permissioned proof-of-authority validator set; more than two thirds must pre-commit before a block is final | Inherits Ethereum’s security through fault proofs, with a security council |
| Execution client | Reth | base-reth-node — the same Rust Ethereum client |
| Gas | USDC, priced in dollars. On Arc, USDC carries 18 decimals natively rather than 6, and the mempool enforces a 20 Gwei floor on maxFeePerGas | ETH. There is no Base token |
| Speed | Deterministic finality in under a second; a documented benchmark of more than 3,000 transactions a second with 20 validators, under 350 ms | Two-second blocks, with Flashblocks running a priority-fee auction and issuing preconfirmations every 200 ms |
| Who orders a transaction | Eleven named institutions and Circle, by permission | Coinbase’s sequencer, whose fees are Coinbase revenue |
| Its own token | ARC, 10 billion minted at genesis, not publicly launched and not promised | None, and none announced |
| Size, 17 Sep 2026 | US$0.33bn of value in decentralised finance, on its second day | US$14.53bn secured, more than any other rollup, of which US$5.54bn is in decentralised finance |
The law
The clarity being invoked is not yet in force
- Circle’s launch release cites “the regulatory clarity of the GENIUS Act”. The Act’s own section 20 makes it effective on the earlier of 18 months after enactment — 18 January 2027 — or 120 days after final implementing regulations.
- From 18 July 2028 a digital asset service provider may not offer a payment stablecoin in the United States unless a permitted issuer issued it. That is the deadline the charters are being collected against.
- The CLARITY Act, which would have settled market structure around all of this, failed a procedural vote the day before Arc opened.
The counting
Two honest numbers for the same chain, differing by a factor of 2.6
- Base secures US$14.53bn by L2BEAT’s count of total value secured, and holds US$5.54bn by DefiLlama’s count of value locked in decentralised finance. Both are correct; they answer different questions, and a comparison that mixes them is worthless.
- On the stablecoin float, the two counts agree: DefiLlama puts USDC at US$73.84bn and Circle’s own release the day before said “more than US$74 billion”. USDC is 23.62% of a US$312.6bn market; USDT is 58.62%.
The stack
The rivals converged on the same engine
- Arc’s execution layer is Reth. Base builds its blocks with
base-reth-node. The difference between an institutional Layer 1 and a consumer Layer 2 is not the virtual machine and not the client; it is who may order a transaction, and in what currency the ordering is paid for. - Base reached that client by leaving Optimism’s OP Stack in February 2026. The original arrangement granted Base up to about 118 million OP tokens over six years in exchange for a share of sequencer revenue; CoinDesk reported it was unclear what the change means for it, and nothing read here settles that.
- Arc’s execution layer is Reth. Base builds its blocks with
Conclusion
So what which chain suits which need — not which one wins
Choose Arc when
The cost of a transaction has to be a number in dollars
- Its strongest point: gas in USDC removes the one thing a treasurer cannot budget for on a public chain — a fee denominated in an asset that moves. Deterministic finality under a second means a settlement is either done or not, with no reorganisation to wait out.
- What comes with it: eleven named institutions and Circle decide transaction order, by permission. That is exactly what makes a bank comfortable and exactly what a reader who values a permissionless chain is giving up. Deployment is open; validation is not.
- And it is two days old. US$0.33bn of value, against a testnet record and a hundred named builders. Nothing about day-one participation tells you what settles there in a year.
Choose Base when
You need the users, the liquidity and Ethereum behind you
- Its strongest point: it is where the value already is. US$14.53bn secured, more than any other rollup, of which US$5.54bn is working in decentralised finance — and security inherited from Ethereum rather than granted by a list of names.
- What comes with it: gas is ETH, so the cost of a transaction is a price you do not set, and a sequencer run by Coinbase orders it. Preconfirmations every 200 ms make that fast; they do not make it neutral.
- And its foundations moved this year. Base left the OP Stack in February for a codebase of its own. It still says it will stay compatible with OP Stack standards, and what became of the OP token arrangement behind it is not settled in anything read here.
Hold the launch-day share price loosely
CRCL fell 6.78% on the day Arc opened. It fell 11.41% the day before, on a Senate vote, alongside a 10.10% fall in Coinbase and a 3.26% fall in bitcoin. Nothing read here connects the launch to the price, and the larger move came first.
The rate moved the other way
A stablecoin issuer whose revenue is interest on reserves is usually read as a bet against rate cuts. On the day Arc launched the Federal Reserve raised its target range by a quarter point, unanimously, saying inflation remains elevated. Circle’s reserve return rate had fallen from 5.0% to 4.1% over 2025; this is the first move in the other direction inside this article’s window.
And the question that decides it is not on either chain
Whether a consortium can move reserve earnings from the issuer to the distributors, and whether a statute written for issuers is amended to notice that distributors pay yields too. Arc is a serious piece of infrastructure. It is not an answer to either.