Could Bitcoin Ever Break the 21 Million Cap? Adam Back Says It’s a Trap

A fresh fight over Bitcoin’s 21 million supply cap has pulled Adam Back and Peter Todd onto opposite sides, after Todd’s case for a permanent block reward resurfaced this week.

Todd wants a small, never-ending issuance to keep paying miners once the last new Bitcoin arrives around 2140. Back reads the argument as a trap dressed up as engineering.

Why Peter Todd Says Bitcoin Needs a Permanent Block Reward

Bitcoin pays miners in two ways. Block subsidies mint new coins, and transaction fees ride along with each block. However, the subsidy is roughly halved every four years, and it hits zero around 2140. Fees alone must carry security after that.

Todd argues fee revenue swings too wildly to hold the chain together. Miners would be incentivized to reorganize the chain and re-mine fat-fee blocks rather than build forward. A fixed reward, he says, kills that pull.

His case leans on lost coins. Todd models supply against a loss rate and finds it settles at a ceiling, because coins vanish as fast as fresh ones appear. Therefore, he frames tail emission as a stabilizer, not inflation.

He has pointed to Monero, which already runs a small permanent reward. Its apparent inflation rate keeps sliding toward zero. The Bitcoin++ conference account resurfaced his talk on the topic this week, which reopened the argument.

The timing matters less than the mechanism. Miners currently earn 3.125 bitcoin per block, and close to 30 more halvings sit ahead. Each one thins the subsidy further while fees stay lumpy and unpredictable.

Adam Back Warns of False Narratives

Back rejects the framing outright. Meanwhile, he points to BIP-110, the contentious 2026 soft fork that tried to filter non-payment data out of blocks, as the model for how these campaigns get sold.

trick is finding ways to trigger and rally people to your dangerously inadvisable cause with simple though false narrarives. 110 used 1) JPEG spam and illegal comtent could be stopped but devs are captured so they won't, 2) anti layer2 anchors devs want to etheriumize bitcoin.

— Adam Back (@adam3us) August 15, 2026

That pattern has a recent scoreboard. The failed BIP-110 fork died after two blocks this month, with miner support near 2.53% against a 55% bar. Back had predicted the stall weeks earlier, and backers now chase a breakaway coin instead.

Bitcoin commentator Trey Sellers made the parallel explicit, writing that a supply-schedule fork would fail as hard as BIP-110, if not harder. Michael Saylor had raised a related worry, warning about protocol neutrality whenever consensus rules bend to one camp.

Still, the security question survives the politics. Bitcoin Knots developers spent August claiming the network faces attack, while miner incentive disputes drew in former Ripple CTO David Schwartz. In contrast to those fights, this one carries no deadline.

One difference cuts against Todd. BIP-110 asked for a soft fork, which needs only miner cooperation. Raising the cap demands a hard fork, and every holder would have to accept it.

Fees may yet fund the chain on their own. Nobody alive today will see that test settled.