The day when the last Bitcoin is mined is not the end, but the beginning of Bitcoin's ultimate test. When the block subsidy returns to zero, can the network still hold up? This article is from an article written by Coingecko and compiled, edited and written by PANews. (Previous: Crypto Market Q2 Report: Bitcoin hits a new high, Circle IPO is listed, DEX transactions explode... Seven highlights of the industry at once) (Background supplement: Bitcoin's upward momentum has stalled, Trump's second son Eric Trump once again called for "buying the bottom of BTC", and CZ's bullish indicator also appeared?) At some time around 2140, there will be no new Bitcoins issued in the market. All 21 million Bitcoins will be distributed, which means Bitcoin miners will only be rewarded in the form of transaction fees. Critics argue that transaction fees alone are not enough to keep the Bitcoin network secure. Key Points After 2140, block subsidies will no longer exist. Bitcoin miners, who are essential for processing transactions and securing the network, will then be paid only through transaction fees paid by users. The gradual reduction of mining fees calls into question the long-term security of Bitcoin, as mining fees act as the Bitcoin network's "security budget." A reduction in the security budget could put the Bitcoin network at risk of a 51% attack and/or lead to greater centralization of the network. Bulls believe that the rise in the value of the Bitcoin asset and the increase in demand for future blocks will make a transaction fee-only market economically viable for Bitcoin miners. Bitcoin's most famous property is its scarcity, which has earned it the title of "digital gold." To ensure scarcity, the rewards paid to Bitcoin miners gradually decrease every four years through the "Bitcoin halving." But this mechanism brings a serious long-term challenge. The Bitcoin network's main incentive for miners: the reward for newly generated Bitcoins, the so-called block subsidy, will completely disappear in about 2140 through the Bitcoin halving mechanism described above. The block subsidy essentially acts as Bitcoin's security budget, paid to miners to ensure the security of the Bitcoin network. This raises a question: Are the remaining transaction fee incentives sufficient to ensure the security of the network? Understanding Bitcoin's Incentive Model To understand the challenges of the post-subsidy era, it is necessary to examine the current incentive mechanism that secures the Bitcoin network. Every ten minutes, a miner verifies a new block of transactions and receives a block reward, which consists of two parts. Block Subsidy: This is a predetermined amount of newly created Bitcoins. When Bitcoin was first launched, the subsidy was 50 Bitcoins per block. It is reduced by half every four years, an event known as the Bitcoin Halving. This mechanism distributes the 21 million Bitcoins over decades and is the primary source of revenue for miners to date. Transaction Fees: This is a fee that users include in their transactions to incentivize miners to add them to the block. You can think of it as an extra "tip" paid to Bitcoin miners to help users who want to ensure their transactions are completed smoothly, thus creating a competitive market environment. As of this writing, the average Bitcoin transaction fee is $1.30 per transaction. Bitcoin Halving: Reducing the Issuance Rate Each Bitcoin halving is a periodic efficiency test for the mining industry, as each halving effectively cuts miners' income in half. This ensures that only the most efficient miners are profitable, and less efficient miners may shut down, but the potential negative effect is that this may temporarily cause the hashrate of the entire network to drop. The Bitcoin network hashrate is the total computing power used to ensure the security of the Bitcoin network. When Bitcoin miners stop working, the hashrate will drop. The reduction in network hashrate means that the Bitcoin network is more vulnerable to network attacks such as a 51% attack (i.e. a single entity controls enough hashrate to disrupt the blockchain). Table 1: Predictable decay of Bitcoin block subsidies over time Bitcoin block rewards in 2025 To further illustrate the importance of Bitcoin block subsidies to miners, here is a breakdown of the rewards for successfully mining a Bitcoin block. According to the blockchain's transaction fee data, in July 2025, each new Bitcoin block contains approximately 0.025 Bitcoin in transaction fees. As of April 2024, the block subsidy is 3.125 bitcoins. In summary, the "wage" of a Bitcoin miner for mining a block is: Guaranteed reward (newly generated bitcoins): 3.125 bitcoins Additional "tips" (from transaction fees): about 0.025 bitcoins Total revenue per block: about 3.15 bitcoins. The "tips" from transaction fees are only a tiny part of the miner's total income, which means that in a market that relies solely on transaction fees, miners are almost certainly not profitable. Discussion of the Economic Viability of Bitcoin in a Post-Subsidy Era Bitcoin transaction fees alone are not sufficient to secure the Bitcoin network in the current market. However, bulls argue that by 2140, demand will drive transaction fees far above current levels, while bears foresee a crisis. The main arguments for each view are discussed below. Table 2: Summary of the Contested Views Pessimistic View: Shrinking Security Budget The basis for the pessimistic view is simple: the historical trend of transaction fees has not shown an increase large enough to compensate for the reduction in subsidies. Critics worry that each halving will reduce the security budget, making the network less secure over time. Optimistic Thesis: Strong Fee Market Optimists believe that Bitcoin will be supported by its rising asset value and growing block demand. First, with the help of Bitcoin's deflationary design, the network will develop into a multi-trillion dollar asset class, so even a small percentage of Bitcoin fees will generate significant income for miners in the future. Second,There will be a fundamental increase in demand for blockspace itself. This could come in the form of large institutional settlements, Layer 2 rollups, or some new innovation yet to be discovered. Ultimately, these factors will drive transaction fees higher, making them economically viable in the future. Potential Risks of a Reduced Security Budget A drop in the security budget could cause a large number of Bitcoin miners to shut down, reducing the total computing power of the Bitcoin network, which would raise a series of potential risks and put pressure on the integrity of the network. 51% Attack The most concerned threat is a 51% attack, where an entity controlling more than half of the network's computing power is able to reverse transactions (double spends) or censor the network. The security budget is a major line of defense; the higher the budget, the more hashrate it supports, and the more expensive the attack becomes. Today, the cost of launching such an attack is prohibitive for a rational economic agent, as it would likely cause the price of Bitcoin to plummet, reducing the value of the attacker's own hardware. However, for geopolitical reasons, nation-state actors might be willing to take such a loss to disrupt the network. As the security budget decreases, the cost of an attack decreases, making this threat more likely in the long term. Hashrate Fluctuations A more immediate risk is miner capitulation, where a large number of miners shut down their machines due to a drop in revenue from the Bitcoin halving, causing a sharp drop in hashrate. While difficulty adjustments will correct for this, the rapid evacuation of miners could create a vulnerable window in the short term.