The Final Bitcoin Will Be Mined in 2140

Sometime in the future around the year 2140, no more Bitcoins will be issued in the market. All 21 million Bitcoins would have been distributed and this means that Bitcoin miners will now only receive rewards in the form of transaction fees. Critics argue that transaction fees alone will be insufficient to maintain Bitcoin’s network security. 

Key Takeaways

• After the year 2140, the block subsidy will cease to exist. Bitcoin miners, who are essential for processing transactions and securing the network, will be compensated exclusively through transaction fees paid by users.

• The gradual decrease in mining fees puts Bitcoin’s long-term security in question because mining fees act as the Bitcoin network’s “security budget”.

• A decreased security budget potentially opens up the Bitcoin network to 51% attacks and/or makes the network more centralized.

• Bulls argue that Bitcoin’s rising asset value and future increased block demand will make a transaction fee-only market financially viable for Bitcoin miners.

A Doomed Future for Bitcoin?

Bitcoin’s most celebrated feature is its mathematical scarcity, which has earned it the moniker “digital gold.” To ensure scarcity, the rewards paid out to Bitcoin miners are gradually decreased every four years through an event called the “Bitcoin halving”. But this system creates a critical, long-term challenge.

The network’s primary incentive for miners, the reward of newly created bitcoins, known as the block subsidy, is designed to disappear completely around the year 2140 through the aforementioned Bitcoin halving. The block subsidy essentially acts as Bitcoin’s security budget, paid to miners to ensure Bitcoin’s network remains secure. Which raises the question: 

Will the remaining incentive of transaction fees be enough to secure the network?

Understanding Bitcoin’s Incentive Model

To understand the challenges of a post-subsidy world, we need to look at the current incentive model that secures the Bitcoin network. Every ten minutes, a miner validates a new block of transactions and receives a block reward, which is composed of two components.

1. The Block Subsidy: This is a predetermined amount of newly created bitcoin. When Bitcoin was first launched, the subsidy was 50 BTC per block. Which decreases and gets “halved” every four years. This is the event that is known as the “Bitcoin halving”. This mechanism distributes the 21 million Bitcoins over many decades and is the primary driver of miner revenue so far.

2. Transaction Fees: These are fees users include with their transactions to incentivize miners to add them to a block.  You may think of this as additional “tips” paid to Bitcoin miners, for users who want to guarantee their transaction goes through, creating a competitive marketplace. The average Bitcoin transaction fee at the time of writing is $1.30/transaction.

Bitcoin Halving: Reducing the Issuance Rate

Each Bitcoin halving is a recurring efficiency test on the mining industry, as each halving essentially also halves a Bitcoin miner’s revenue every four years. This ensures that only the most efficient miners remain profitable and less efficient miners may shut down, but a potential negative side effect is that it may temporarily cause the total network hashrate to drop. 

Bitcoin’s network hashrate is the total computational power being used to secure the Bitcoin network, which drops when Bitcoin miners shut down. A decrease in network hashrate means that the Bitcoin network is more susceptible to cyber attacks such as a 51% Attack (where a single entity controls enough power to disrupt the blockchain).

Table 1: The predictable decay of the Bitcoin block subsidy over time, illustrating the programmed path to a finite supply and a fee-only security model.

Bitcoin Block Rewards in 2025

To further illustrate the importance of the Bitcoin block subsidy to Bitcoin miners, below is a breakdown of their reward for successfully mining a Bitcoin block. 

Using transaction fee data from Blockchain, in July 2025, each new Bitcoin block contains roughly 0.025 BTC in transaction fees. The block subsidy as of April 2024, is 3.125 BTC.

In summary, a Bitcoin miner’s “paycheck” for one block:

1. Guaranteed Reward (newly created bitcoin): 3.125 BTC
2. Extra “Tips” (from transaction fees): ~0.025 BTC

Total Earnings Per Block: ~3.15 BTC

As you can see, the “tips” from transaction fees make up a tiny fraction of a miner’s total earnings, meaning they will almost certainly not be profitable in a transaction fees only market.

Debating Bitcoin’s Financial Viability in a Post-Subsidy World

We know that Bitcoin transaction fees alone are insufficient to ensure the security of the Bitcoin network in today’s market. However, Bulls believe that by 2140, demand will drive transaction fees to levels far higher than today, while Bears foresee a crisis. Below, we explore the major arguments for each case.

Table 2: A summary of the competing arguments in the Bitcoin security budget debate.

The Bear Case: A Shrinking Security Budget

The pessimistic argument is rooted in a simple observation: transaction fees have not historically shown a trend of rising enough to compensate for the declining subsidy. Critics worry that each halving will chip away at the security budget, making the network progressively less secure.

The Bull Case: A Robust Fee Market

The optimistic view argues that Bitcoin will be supported by its rising asset value and increased block demand. Firstly, they argue that with the help of Bitcoin’s deflationary design, the network would mature into a multi-trillion dollar asset class such that even fractional BTC fees translate into substantial revenue for Bitcoin miners in the future. 

Secondly, they also argue that there will be a fundamental increase in the demand for block space itself, which may come in the form of large institutional settlements, Layer 2 rollups or perhaps some new innovation not yet discovered. Ultimately these factors would drive up transaction fees to become financially viable in the future.

Potential Risks of a Decreased Security Budget

A declining security budget, which may lead to too many Bitcoin miners shutting down, thereby decreasing Bitcoin’s total network hashrate, creates a cascade of potential risks that could stress the network’s integrity.

The 51% Attack

The most discussed threat is a 51% attack, where an entity controlling over half the network’s hashrate could reverse transactions (double-spend) or censor the network. The security budget is the primary defense; a higher budget supports more hashrate, making an attack more expensive. Today, an attack would be prohibitively costly for a rational economic actor, as it would likely crash the price of Bitcoin and devalue the attacker’s own hardware. However, a state-level actor might be willing to absorb such losses to sabotage the network for geopolitical reasons. As the security budget falls, the cost of an attack decreases, making this threat more plausible over the long term.

Hashrate Volatility

A more immediate risk is miner capitulation, where a revenue drop (from the Bitcoin halving) forces a large number of miners to shut down, causing a sharp decline in hashrate. While the difficulty adjustment corrects for this, a rapid exodus could create a temporary window of vulnerability.

Bitcoin Innovation as a Solution

The Bitcoin community is actively developing solutions to grow network adoption and mitigate the risks of Bitcoin’s gradually decreasing security budget. Below are some of these solutions.

Layer 2 Solutions

One solution to Bitcoin’s limited on-chain capacity are Layer 2 (L2) blockchains. L2s are sub-blockchains built within the main blockchain (Bitcoin in this case) that offshores transactions from the main blockchain to these L2s for improved transaction speeds and costs. 

L2 solutions like the Lightning Network enable Bitcoin to be used for everyday transactions, which has seen some adoption in Vietnam. Bitcoin Saigon, Vietnam’s Bitcoin community regularly promotes and partners up with local merchants, coffee shops and markets where Bitcoin payments powered by the Lightning Network are accepted. If L2s are successful, this will drive network adoption to everyday adoption which would translate into higher transaction fees on the main Bitcoin blockchain network.

Bitcoin Runes

Popularized in 2024, Runes is a token standard that utilizes Bitcoin’s UTXO model (where a wallet’s balance is made up of individual chunks of unspent bitcoin, much like physical coins and bills in a wallet) and the OP_RETURN opcode (a function that allows for a small amount of data to be embedded into a Bitcoin transaction, similar to a memo field on a check). Runes enables the creation of memecoins and community tokens on the Bitcoin blockchain. At its peak, Runes sent average Bitcoin transaction fees to a record high of $127 per transaction. While market interest in Runes has faded, this innovation showcases how new use cases could potentially push Bitcoin transaction fees up, paving the way for a fee-only Bitcoin economy in the future.

The Future User Experience

For the average user, interacting with Bitcoin will likely be a multi-layered experience. Sending a transaction directly on Layer 1 is expected to become expensive, reserved for high-value transfers. For daily commerce, users will almost certainly interact with Bitcoin through a Layer 2 solution like the Lightning Network, which provides an instant, low-cost experience or use Wrapped Bitcoins instead. This shift means the user experience for small payments will remain viable, but it will happen on a different technical layer than the main blockchain.

The Investor’s Long-Term Outlook

For investors, the end of the block subsidy introduces a critical tension between two of Bitcoin’s core attributes: scarcity and security. Investors are drawn to Bitcoin’s fixed supply, but they must now contend with the reality that the network’s security is dynamic and will depend on a future fee market.The long-term value of a scarce asset is questionable if the network securing it is perceived as vulnerable. Ultimately, the value of Bitcoin will be derived not just from its technical properties but from the market’s collective confidence in its ability to remain secure.

Conclusion

The day the last new bitcoin is mined will not mark the end of Bitcoin, but the beginning of its ultimate test. The end of the block subsidy is the protocol’s intended final state, a challenge for which the ecosystem has over a century to adapt to. Bitcoin’s long-term security will be determined by a complex interplay of forces: technological innovation in Layer 2 solutions, the economic evolution of a robust fee market, and the social consensus around Bitcoin’s role as a global settlement layer. Note that this article discusses the potential concerns of Bitcoin’s far fetched future, it is highly speculative in nature given the century long gap between now and 2140. This article is only meant for educational purposes and should not be taken as financial advice. Featured projects are not endorsed.