Sweeper bots burn $4,800 in Bitcoin fees chasing $12.67
Automated sweeper bots spent about $4,800 in Bitcoin transaction fees in January 2026 to capture $12.67 from a compromised address.The bots fought hard for that prize. The miner, who collected the fees, did considerably better.The target was a SegWit address whose private key was effectively public. Whoever set it up used the coinbase transaction ID from Bitcoin block 924,982 as the key.A coinbase transaction is the first transaction in every block, the one that pays the miner. Its ID is visible to anyone who looks at the blockchain. That made the key derivable by anyone running the right script. Any coins sent to the address were claimable by whoever moved first.Two small deposits arrived. The first was 0.00018209 BTC, and the second was 0.00002096 BTC, for a combined total of 0.00020305 BTC.Both were swept within minutes of being sent. The address finished with a zero balance and no remaining unspent outputs, known as UTXOs.The expensive part was the competition. Several bots spotted the same deposits at once, and each tried to claim them.They did it using replace-by-fee, or RBF. This Bitcoin feature lets a sender swap an unconfirmed transaction for a new version that pays a higher fee. Miners generally prefer the higher-paying version, so the replacement tends to win.According to the research findings, fee rates hit 12.8 sat/vB on the first sweep and 4.80 sat/vB on the second. Sat/vB stands for satoshis per virtual byte, the standard unit for pricing block space.When the dust settled, the bots had collectively spent about $4,800 in fees to net $12.67. Most of those fees went to miners.No identifiable person or entity has been tied to the incident. There is no named victim, no known bot operator, and no public explanation for why someone built a wallet on a key pulled from a block's coinbase transaction.Similar RBF bidding wars have reportedly played out on other weak-key addresses, including some involving larger sums. This one stands out mainly for its absurd ratio of cost to reward.For bot operators, the economics look shaky. Spending roughly 380 times the value of the prize is not a business model. The research findings note that losses like this limit the profitability of sweeper activity. If enough bots keep colliding on tiny deposits, some operators may have to add stop-loss logic that caps how much they will pay to win a sweep.Miners, meanwhile, are the quiet beneficiaries. They did nothing unusual. They simply included the highest-paying transactions, as they always do, and collected thousands of dollars in fees on a few cents' worth of movement.RBF exists so users can speed up stuck transactions when the network is busy. In the hands of competing bots, the same tool becomes a fee escalator that transfers value straight to block producers.