Harmony’s ONE Crashes Up to 34% After Exploit Mints 4B Tokens, 26% of Supply

Harmony’s ONE token plunged as much as 33.9% in the past 24 hours after an apparent exploit minted roughly 4 billion new tokens, an amount equal to about 26% of the network’s prior circulating supply of roughly 15 billion ONE. The layer-1 blockchain confirmed it is working with exchanges to freeze the funds and is preparing both a software patch and a possible rollback of the chain.

Harmony said in a post on X that it is “working on a patch and rollback options” and would provide further updates once more information is available. The team has not yet confirmed the root cause of the mint, the exact number of tokens created, or how much reached exchange wallets.

What the numbers show

Estimates on price impact diverge slightly by source and timeframe: CoinGecko data cited by one outlet put the 24-hour drop at 33.9%, while another reported a 26% decline during Asian morning trading hours. Either figure marks a severe, exchange-wide repricing of ONE as the market absorbed news of the sudden supply expansion.

An X account tracking the incident, “Juiceberg,” claimed the unauthorized tokens were created through empty blocks and that approximately 2.8 billion ONE were quickly funneled to exchanges as the price fell. The same account estimated the attacker still held about 115 million ONE onchain — roughly 2.9% of the alleged minted total — with the rest either sold or sitting in exchange deposit wallets. These figures have not been independently verified by Harmony or by either reporting outlet.

Rollback on the table — and its trade-offs

A rollback would reset Harmony’s blockchain to a state before the exploit, effectively erasing subsequent transactions from the chain’s accepted history. That approach can strip an attacker of freshly minted tokens still sitting on the network, but it loses effectiveness once funds have already moved to exchanges or bridged to other chains — which appears to be the case here, given the reported outflows.

A rollback also cuts against blockchain’s foundational promise of immutability, and many in the industry view forced chain reversals as a last resort that can undermine trust in a network even as it limits an attacker’s gains.

Not Harmony’s first security scare

The exploit adds to a troubled security history for Harmony. In June 2022, the network’s Horizon Bridge was drained of roughly $100 million, an attack the FBI later attributed to North Korea’s Lazarus Group. In 2023, a separate bug improperly minted about 146.3 million ONE tokens.

The latest incident also follows a security event at Ravencoin, a smaller blockchain, which reportedly hit a record low after a network exploit put transactions at risk just a day earlier — underscoring a rough stretch for smaller layer-1 chains.

Why it matters for holders

For ONE holders, the core risk is dilution: a 26% jump in supply, even if temporarily reversed, signals a fundamental breach of the network’s monetary policy and token scarcity. Traders should watch whether exchanges succeed in freezing the alleged proceeds and whether Harmony ultimately executes a rollback, since either outcome will directly shape how much of the newly created supply re-enters circulation and continues to pressure ONE’s price.

Sources

• cointelegraph.com
• coindesk.com