A wallet that trusts Arc's declared 18 decimals renders one dollar as 0.000000000001

The gap between those two reads is twelve decimal places. The node keeps the native ledger at 18 decimals, and the contract at 0x3600...0000 that presents the same coin keeps 6 ^[12]. Divide the first figure by 1e12 and it matches the second to the unit, so Arc has one balance with two interfaces, not a coin and a wrapper ^[14]. In dollars, the pool held $3,692,022.800475 ^[13].

The display path is where that bites. `nativeCurrency.decimals: 18` is chain precision, so a wallet that adds Arc from the standard network parameters and believes the field puts a one-dollar balance on screen as 0.000000000001 ^[16]. Arc's own wallet guide tells integrators to divide by 10^12, label the result USDC instead of ETH, and merge the native and ERC-20 rows into one ^[17]. The network-parameters page warns that a wallet without custom-gas-token support "may display balances as ETH" ^[18]. Suliman Mukhtar, writing on dev.to, took all six of his figures from the node, and says they were not in the launch posts ^[25][2].

The base fee sat at 20 gwei, and the block header's `extraData` was eight bytes equal to it. Arc is publishing the next block's base fee in the parent header ^[7][8]. At 18 decimals a dollar is 1e18 base units, so 20 gwei works out at two hundred-millionths of a dollar per unit of gas ^[21]. That is $0.02 per million gas, and $0.60 to fill the 30,000,000-gas block ^[23][22]. The figure holds only while the base fee stays pinned, and the validator set that pins it is twelve named institutions running proof of authority, Circle plus BlackRock, DTCC, Visa, Mastercard, ICE and six more ^[10][4].

The block Mukhtar pinned used 213,828 of 30,000,000 gas. That is 0.7% ^[7][24]. His own summary line says 3-11% used ^[10].

For anyone deploying, the reads are encouraging. Multicall3, Permit2, the CREATE2 deterministic deployer and Safe v1.4.1 sit at their canonical addresses, and the MetaMask, Alchemy and Uniswap EIP-7702 delegator contracts hold code; the docs attribute that to the EVM being at the Osaka fork ^[11]. `eth_getCode` at 0x...006b returned 0x, so the Arbitrum precompile is absent and this is not a Nitro chain ^[9]. `web3_clientVersion` answers "arc/v1", which Mukhtar describes as a Reth-based client under Malachite BFT consensus ^[6].

Indexers get the other integration bug. The ERC-20 face emits `Transfer` events for native movements, four of them in the pinned block. That is EIP-7708 in practice, so a pipeline ingesting native sends and those logs books every transfer twice ^[15]. The contract is 1,798 bytes, is not a proxy, and its bytecode holds none of the `blacklist`, `isBlacklisted`, `pause` or `mint` selectors mainnet USDC is known for ^[19]. Mukhtar wrote that this "does not mean there is no freeze on Arc; it means the freeze, if it exists, is not in this contract" ^[20].