Bitcoin’s mining sector is facing a twin pressure point in 2025: transaction fee income has fallen to its lowest share of total miner revenue in a decade, while miners have sold roughly $1.78 billion worth of BTC, adding to persistent market oversupply.
According to data from The Block, transaction fees now account for less than 0.7% of total miner revenue, the lowest level since 2015. The overwhelming majority of miner income still comes from the block subsidy. The decline in fee contribution reflects reduced main-chain congestion, increased use of layer-2 solutions such as the Lightning Network, and the fading impact of Ordinals and BRC-20 token activity, which briefly spiked fees in 2023.
The low-fee environment is a double-edged sword. It signals a less congested, cheaper network, but it also increases miner dependence on the block subsidy. That dependence becomes more concerning ahead of the next Bitcoin halving, expected in 2028, when the block subsidy will drop from 3.125 BTC to 1.5625 BTC per block. If fee income does not recover, less efficient miners could be forced out, raising concerns about network centralization and long-term security.
Separately, a CoinDesk analysis found that listed mining firms have reduced their combined Bitcoin holdings from about 127,000 BTC at the start of the year to 99,000 BTC currently, implying sales of around 28,000 BTC worth approximately $1.78 billion. This miner selling has been quieter than the more visible outflows from U.S. spot Bitcoin ETFs, which have surpassed $4.4 billion in net outflows this year, but it has nonetheless exacerbated market weakness.
Long-term holders and Bitcoin treasury companies, including Strategy (MSTR), have also been net sellers. In a low-liquidity environment, steady disposal by miners can move prices more than it would during periods of strong demand, keeping Bitcoin’s recovery attempts capped.
For investors, the combination of shrinking fee revenue and sustained miner distribution underscores the challenging supply-demand backdrop for Bitcoin in 2025. While miner selling is a normal part of covering electricity and hardware costs, its scale this year is notable and adds to the broader headwinds facing the market.
