A Bitcoin user has reportedly lost nearly $60,000 in transaction fees after making a critical error while using Bitcoin’s “Replace-by-Fee” (RBF) feature. The incident, which occurred shortly after midnight UTC on April 8, involved a transaction where the user mistakenly included almost 0.75 BTC as a fee—an amount significantly higher than what is typically required.

The original transaction attempted to send 0.48 BTC (around $37,770) and leave behind 0.2 BTC ($16,357) as change. However, the fee set in a later RBF transaction ended up absorbing the entire change output—effectively burning the user’s funds in the process. Anmol Jain, VP of Investigations at crypto forensics firm AMLBot, noted that the user may have intended to input a smaller fee but accidentally entered a much larger one, possibly due to haste or confusion between sat/vB (satoshis per virtual byte) and total satoshis.

Experts suggest that a bug in an automated script or a misinterpretation of wallet settings could also be to blame. RBF, which allows users to replace an unconfirmed transaction with another one offering a higher fee, is often misunderstood. While it's meant to prioritize transactions in Bitcoin’s mempool, it can backfire if misused.

This costly mistake reignites debates around RBF’s risks and complexities. Critics argue that the feature can enable double-spending and introduces user error, while others say it’s an essential tool for managing congested networks.

The case serves as a stark reminder of the importance of understanding crypto transaction mechanics—especially when dealing with large sums. One small mistake in the fee field can lead to massive, irreversible losses in the blockchain world.