Harmony's validators will rewind the chain to a block recorded at 11:25 p.m. UTC on Aug. 11, erasing every transaction confirmed after that point. The network announced the decision Monday after investigators confirmed that an exploit had generated unauthorized ONE tokens and pushed them across the network.
The rollback window covers 109,126 regular transactions and 315 staking transactions. Those interactions—transfers, contract calls, nonce increments—will be treated as if they never occurred. Replacement databases will serve as the foundation for new blocks produced from the next block height after the checkpoint.
Harmony said a surgical approach—selectively restoring certain transactions while discarding others—was not viable. Balances, contract states and nonces on the replacement chain would diverge from those on the pre-exploit chain, creating inconsistent state that downstream applications and bridges would be unable to reconcile.
The exploit centered on the minting of forged ONE tokens. Harmony had flagged the incident the prior week, when reports surfaced that unauthorized ONE had been created and sent to exchanges. By Monday's announcement, investigators said they had traced nearly all of the forged supply to specific wallets or service entry points and were coordinating with exchanges, bridge operators and law enforcement to contain and freeze the affected assets.
At current prices, ONE carries a market cap of roughly $10.8 million. The token's thin liquidity makes the forged supply a proportionally large problem—even a moderate quantity of fabricated tokens can move markets or drain exchange order books before detection.
The rollback places Harmony alongside Ravencoin, which faces its own reorganization dispute following a separate consensus exploit. Mining pools commanding the majority of Ravencoin's hash rate began constructing a competing chain capable of reversing previously confirmed transactions. Ravencoin trades at $0.002819, giving it a market cap of $46.3 million—roughly four times Harmony's current figure.
The two cases arrive as on-chain immutability is already under debate across DeFi. A rollback is the bluntest available tool: it preserves the integrity of the canonical state at the cost of erasing legitimate user activity confirmed after the chosen block. Every wallet that sent tokens, every LP that adjusted a position, every staker who updated delegation during the 109,000-transaction window loses that on-chain record.
The staking transaction count—315 in the discarded window—is relevant beyond simple accounting. Staking state on a proof-of-stake chain affects validator set composition, delegation balances and reward accrual. Rolling back staking transactions means those validator-level state changes revert as well, not just user balances.
For any protocol or bridge that settled against Harmony during the affected window, the replacement chain creates a reconciliation problem. Assets that moved cross-chain based on transactions now being erased have no corresponding on-chain anchor on the reverted Harmony state. Bridge operators working with Harmony's incident response team will need to determine how to handle those positions individually.
Harmony has not published a specific timeline for when the replacement chain goes live, but the Monday announcement framed the checkpoint reversion as the confirmed course of action rather than an option under consideration. The network had described a rollback as a possibility the previous week—Monday's statement moved it to a decision.
The Ravencoin situation remains less resolved. A competing chain being built by major mining pools introduces a miner-governance dimension absent from Harmony's validator-led process. In Ravencoin's proof-of-work model, the chain with the most accumulated work wins by protocol rules—meaning the outcome depends on which version of the chain the hash rate majority ultimately supports, not on a network announcement.
