A Bitcoin user incurs a $3.1 million transaction fee for transferring 139 BTC.

A developer from the mempool suggested that the user initiating the transfer may be unaware of the non-cancellation policy for replacement fees, leading to an inadvertent $3.1 million transaction fee.

A Bitcoin user incurs a $3.1 million transaction fee for transferring 139 BTC.

A Bitcoin user, utilizing the wallet address bc1qn3d…wekrnl, made a transfer of 139.42 BTC to bc1qyf…km36t4 on November 23, incurring an astonishingly high transaction fee of $3.1 million, marking it as the eighth-highest fee in Bitcoin's 14-year history. The value of BTC at the time was $37,456. The destination address received only 55.77 BTC, prompting intrigue and discussions on social media.

Antpool mining reward history. Source: Mempool

The mining pool Antpool was the recipient of this unusually large mining fee, documented on block 818087. Some users speculated that the sender might have intentionally chosen a high transaction fee, but factors such as the replace-by-fee (RBF) node policy and the sender's potential lack of awareness also contributed to the situation. RBF allows users to replace an unconfirmed transaction with a new one that offers a higher fee, expediting its confirmation. The mempool, where all BTC transactions await approval and inclusion in the Bitcoin blockchain, is central to this process.

A developer from the mempool, identified as mononaut, suggested that the user may not have been aware that RBF orders are irrevocable. The user might have attempted to cancel the transaction by repeatedly replacing the fees. The RBF history reveals that the last replacement increased the fee by an additional 20%, adding 12.54824636 BTC in fees.

RBF history of the 83.7 BTC transaction fee. Source: Mempool

This incident mirrors a previous case in September when the Paxos exchange mistakenly sent a $500,000 transaction fee for a $2,000 BTC transfer. In that scenario, the F2Pool miner who verified the transaction returned the accidental fee to Paxos. However, the current $3.1 million fee stands as the largest ever paid in dollar terms, surpassing the previous record set in September. The mempool developer mentioned that whether Antpool would consider returning the funds depends on their payout policies and obligations to share transaction fees with miners. Antpool has not yet commented on the matter.