Arc Mainnet Opens Tomorrow: What to Watch on Day One

Arc, the Layer 1 built by Circle, opens its public mainnet tomorrow, 16 September 2026. Seven memecoin launch venues have pointed themselves at it ahead of the day, two of them showing tokens or a launch form on a chain that does not yet exist to run them. This piece sets out what the desk will be looking for from the first block, in what order, and how the day's record will be verified. The record itself is appended at the end of this page and filled on the day; until then every figure in it is a placeholder, marked as one.

Arc is a Layer 1 blockchain built by Circle, the issuer of USDC. It uses USDC as its gas token and opens its public mainnet on 16 September 2026. That gas choice is the reason day one on Arc will read differently from day one on any other chain: every fee, every pool and every launch cost will be denominated in the same asset the tokens trade against, so nothing in the record below will need converting through a native coin price.

The field going in

Of the seven venues on this desk's Arc launchpad tracker, none carries the mark "Live" today, because a venue is counted live here only when a token launched through it can be seen trading in a pool on Arc mainnet, and there is no Arc mainnet yet. Two — Arch and ubi.fun — were marked "appears live" on 14 September: a front page showing tokens and a working launch form ahead of the chain they are meant to run on. ARCLaunch and AstraPump are announced with no open product. 5042.fun says on its own site that access is opening soon. Sharc describes a product and gives no signal either way. Bullcheese, TrustSwap's own venue, opens the same day, 16 September 2026, per TrustSwap, the operator.

That spread is the first thing to watch. Two venues have effectively claimed day one in advance; tomorrow is when the claim meets a block explorer.

What the desk will check, in order

Which venues have a confirmed pool. A venue moves from "appears live" to Live on this tracker only against on-chain evidence: a token launched through it, trading in a pool on Arc mainnet, with both the pool and the token contract visible on Arcscan. A front page with tokens on it is not evidence. A deployed contract with no pool is not a launch, and the desk will not count it as one until it finds a market.

Which was first, and by how much. Block times, not announcement times. Whether the ordering matters beyond the first news cycle is the open question of the week — on Robinhood Chain in July, the venue that was effectively the chain's issuance layer for its first eleven days was dark inside a fortnight, and the venue that now leads on fees was not a day-one venue.

The launch count against the traded count. A launch count measures how many people found the button; a traded count measures how many launches found a buyer. The gap between the two is the number worth watching on any new chain, and the desk will report both with the volume floor it used.

What the pools look like. Median first-day liquidity and median first-day volume across confirmed pools, and how concentrated the day was in its top token. On a chain quoted in USDC these are readable directly off the pool pages, which is the one respect in which day one on Arc is easier to report than day one elsewhere.

Lock treatment, venue by venue. How many of the day's tokens carry a published lock record the desk can open and read, and how many do not. The field split three ways before mainnet: liquidity burned or permanently locked at graduation, liquidity permanently locked at launch, and liquidity locked under a third-party contract with the fee stream still claimable. A published lock record protects against one thing — the liquidity being pulled — and this desk will not present it as more than that. It is the difference between a claim a buyer can check and a claim a buyer has to accept.

What breaks. RPC endpoints, the explorer, a venue's launch form, a bridge. Where an incident is reported, it will be reported with the source that observed it and the time; where the desk cannot confirm a report, the entry will say so rather than repeat it as fact.

How this desk will verify day one

A venue is counted live only on the evidence described above. Timestamps are block times. Volume and liquidity figures are read from the pool pages named in Sources, at the times stated — from Arcscan first, and from DexScreener, or any chart that indexes Arc pools, as a cross-check; where the two disagree by more than a stated tolerance, both figures are given. Nothing in the record is sourced to a venue's own announcement alone.

Corrections: the Arc desk logs corrections on this page with the date and what changed.

Sources: arc.io/blog, "Arc Mainnet Launches September 16, 2026" (15 Sep 2026) · Arc launchpad tracker, this desk (14 Sep 2026) · thearch.fun, ubi.fun, sharc.fun, 5042.fun (14 Sep 2026) · arclaunch.fun press materials, openpr, 13 Aug 2026 (14 Sep 2026) · builtonarc.app AstraPump entry (14 Sep 2026) · bullcheese.fun (15 Sep 2026).

Day-one record (updated 16 September)

Bullcheese is a permissionless launch venue. Tokens launched on it are created by anyone, carry no endorsement, and can go to zero. Nothing here is financial advice.

Disclosure: Radian is built by TrustSwap, and Bullcheese is a TrustSwap product.