Bitcoin's mining economy faces an existential threat that has nothing to do with price volatility or energy costs. According to Patrick Shyu, a former engineer at Meta and Google, the network is approaching a breaking point where miners won't earn enough to stay online, potentially weakening Bitcoin's security.

What Is Bitcoin's Security Budget Problem?

The issue centers on how Bitcoin pays the people who secure its network. Miners currently earn rewards in two ways: newly created Bitcoin (called the block subsidy) and transaction fees paid by users. Right now, the block subsidy dominates miner income, but that's about to change dramatically.

Roughly 95% of Bitcoin's 21 million total supply has already been issued, which means the newly minted coins that miners receive are shrinking with each halving event. The next halving is expected in 2028, when the block subsidy will drop from 3.125 BTC to 1.5625 BTC per block. This cut will slice miner rewards in half.

"Miners secure the network, and they have to get paid in two ways: either newly minted coins or your transaction fees. The fee economy they would depend on never showed up," said Patrick Shyu.

Patrick Shyu, Former Engineer at Meta and Google

The problem is that Bitcoin's transaction fee market has never developed into a reliable income source. Fees spike during periods of heavy demand for block space, but during quieter market conditions, they barely cover operational costs. Shyu warned that this gap between declining subsidies and insufficient fees could trigger what he called a "slow death spiral" of weaker mining participation and degraded network security.

How Has Mining Economics Already Started to Deteriorate?

The strain on miners is already visible in recent network data. In June 2026, Bitcoin's mining difficulty fell by 10.09% after lower hashprice and tighter operating margins pushed mining hardware offline. The hashprice is the amount of Bitcoin reward miners earn per unit of computing power, and when it drops, less efficient operations shut down first.

This difficulty reduction is a natural adjustment mechanism in Bitcoin's code, but it signals that profitability has become a real problem. Miners are the canaries in the coal mine for network health, and when they start unplugging equipment, it's a warning sign.

What Are the Long-Term Risks to Bitcoin's Security?

Shyu identified two major threats to Bitcoin's future, which he described as "two ticking time bombs":

• Quantum Computing Risk: Bitcoin's security relies on cryptographic signatures that protect private keys. If quantum computers become powerful enough, they could theoretically calculate private keys from publicly exposed signatures, allowing attackers to steal coins from older addresses that have been spent from onchain.
• Miner Revenue Collapse: As block subsidies decline and transaction fees remain unpredictable, miners may lack sufficient economic incentive to continue securing the network, reducing hashrate and making Bitcoin vulnerable to attacks.

The quantum threat has prompted several Bitcoin Improvement Proposals (BIPs) to address the vulnerability. BIP-360 proposes a new output type that removes certain spending options, while BIP-361 suggests a staged retirement of quantum-vulnerable signature types once a post-quantum alternative becomes available. However, neither proposal has an activation schedule or network-wide approval yet.

The debate has expanded into a contentious discussion about whether dormant Bitcoin holdings that fail to migrate to quantum-resistant formats should eventually be frozen. Charles Hoskinson, founder of Cardano, has challenged this approach, arguing that it could turn older Bitcoin holdings into a property-rights dispute involving millions of exposed coins.

Steps to Understand Bitcoin's Mining Economics

• Block Subsidy Schedule: Bitcoin's block reward halves approximately every four years. Currently at 3.125 BTC per block, it will drop to 1.5625 BTC in 2028, then continue halving until reaching zero around the year 2140.
• Transaction Fee Market: Unlike the predictable block subsidy, transaction fees fluctuate based on network congestion. During bull markets, fees spike; during bear markets, they collapse, leaving miners dependent on the shrinking subsidy.
• Mining Difficulty Adjustment: Bitcoin's difficulty adjusts every 2,016 blocks to maintain a consistent 10-minute block time. When hashrate drops, difficulty falls, making mining easier for remaining operators, but it also signals economic stress in the industry.
• Hashprice Dynamics: Hashprice measures Bitcoin earned per unit of mining power. When hashprice falls below operational costs, miners shut down equipment, reducing network security until difficulty adjusts downward.

Shyu's warning arrives at a critical moment for Bitcoin's long-term viability. The network has operated for over 16 years with a growing block subsidy, but the next decade will test whether transaction fees can sustain mining security once subsidies become negligible. If miners cannot earn enough to cover electricity, hardware, and operational costs, they will exit the network, potentially creating a feedback loop where reduced security makes Bitcoin less valuable, further reducing miner incentives.

The mining industry has already begun adapting to this reality. Recent difficulty reductions show that some miners are already operating at the margin of profitability. Whether Bitcoin's fee market can mature into a sustainable revenue source before the 2028 halving remains one of the most important open questions in cryptocurrency.