Ledgers do not lie, but liquidity always flees. This week, a fresh fight over Bitcoin’s 21 million supply cap pulled Adam Back and Peter Todd onto opposite sides. Todd’s case for a permanent block reward resurfaced via the Bitcoin++ conference account. The market yawned. The code, however, demands attention.
Context: The Halving Schedule and the Security Gap
Bitcoin pays miners two ways. Block subsidies mint new coins. Transaction fees ride along with each block. The subsidy halves every four years. Around 2140, it hits zero. After that, fees alone must carry security. The theory is elegant. The practice is fragile.
Todd argues that fee revenue swings too wildly to hold the chain together. Miners, he says, would be incentivized to reorganize the chain and re-mine fat-fee blocks instead of building forward. A fixed reward—a small, never-ending issuance—kills that pull. His model leans on lost coins. He models supply against a loss rate and finds it settles at a ceiling. Coins vanish as fast as fresh ones appear. Therefore, he frames tail emission as a stabilizer, not inflation. He points to Monero, which already runs a small permanent reward. Its apparent inflation rate keeps sliding toward zero.
Core: The Mechanism Behind the Noise
Miners currently earn 3.125 bitcoin per block. Close to 30 more halvings sit ahead. Each one thins the subsidy further while fees stay lumpy and unpredictable. The timing of this debate matters less than the mechanism. I watched the ape sell; the code still audits. Based on my experience auditing DeFi protocols in 2017, I learned that every economic model has a hidden assumption. Todd’s assumption is that the loss rate of coins is stable and predictable. It is not. Lost coins are a black box. No one knows how many are truly gone versus dormant. The code treats them as unspent outputs. They can be moved at any time if the private key surfaces. Tail emission assumes a constant rate of loss. That is a fragile foundation.
Adam Back rejects the framing outright. He points to BIP-110, the failed 2026 soft fork that tried to filter non-payment data out of blocks. His argument: the same pattern of false narratives is being used to sell a dangerous supply change. BIP-110 died after two blocks with miner support near 2.53% against a 55% bar. Back had predicted the stall. Backers now chase a breakaway coin. The parallel is explicit. A supply-schedule fork would fail as hard, if not harder.
Contrarian: The Real Risk Is Not the Fork
Both sides miss the point. The debate is a distraction. The real risk is not a hard fork that raises the cap. That would require every holder to accept it. The barrier is nearly insurmountable. The real risk is the slow erosion of security through underinvestment in mining as fees fail to compensate. Todd’s solution is a band-aid. Back’s dismissal is political. In the audit, we find the truth that price hides. The truth is that the 21 million cap is a social contract, not a technical invariant. The code can be changed. The question is: will the economic incentives align to change it?
Fee revenue may yet fund the chain on its own. Nobody alive today will see that test settled. But the market is not pricing the security risk. The hashrate is driven by subsidy, not fees. When the subsidy drops below a threshold, miners will exit. The chain will become more centralized. That is a slow-moving crisis. Todd’s proposal is a premature fix. Back’s rebuttal is a defensive posture. The correct answer is to design fee markets that are predictable. That is a harder problem than changing the supply curve.
Takeaway: The Code Will Decide
Strategy is the bridge between chaos and profit. The 21 million cap will hold for the next decade. But the debate will intensify with each halving. The ecosystem must adapt—not through hard forks, but through better fee mechanisms. Trust the protocol, verify the exit. The exit for this debate is not a vote. It is a calculation. The code will show the truth when the subsidy vanishes. Until then, we trade the code, not the culture.