A long-simmering argument over Bitcoin’s hard 21 million coin limit has resurfaced, placing two early network contributors on opposing sides. Developer Peter Todd maintains that a small, permanent block reward will be necessary once the last new coins are mined around 2140. Blockstream CEO Adam Back dismisses the idea as a misleading campaign that risks undermining one of Bitcoin’s core economic rules.

Todd’s Case for Ongoing Issuance

Bitcoin currently compensates miners through a combination of newly created coins, known as the block subsidy, and transaction fees. The subsidy stands at 3.125 bitcoin per block and is programmed to halve roughly every four years until it reaches zero near 2140. After that point, fees alone would have to secure the network.

Todd contends that fee revenue is too volatile to provide reliable incentives. In periods when large fees appear in certain blocks, miners could find it profitable to reorganize the chain and re-mine those blocks rather than extend it forward. He proposes a modest, never-ending issuance—often called tail emission—to remove that incentive.

He further argues that coins lost through forgotten keys and inaccessible wallets would offset the new supply. Under this model, circulating bitcoin could stabilize rather than expand indefinitely. Todd has cited Monero, which already operates with a permanent reward, as evidence that apparent inflation can decline over time while miner payments continue.

Back Rejects the Proposal as a False Narrative

Back has rejected the framing. He described efforts to alter Bitcoin’s supply schedule as attempts to rally support through simplified but inaccurate stories, drawing a parallel to the recent BIP-110 soft-fork campaign.

BIP-110, which sought to filter certain non-payment data from blocks, failed this month after attracting only about 2.53 percent miner support against a 55 percent threshold. Back had earlier predicted its stall. Commentators have noted that any attempt to raise the supply cap would face even steeper obstacles because it would require a hard fork and acceptance by the entire network of users and holders, not merely miners.

Hard Fork Threshold and Distant Timeline

Unlike a soft fork, changing the 21 million limit cannot be activated by miner signaling alone. Every participant would need to adopt the new rules, making consensus far more difficult to achieve.

The security question itself remains unresolved. Fees may prove sufficient once the subsidy disappears, yet no one alive today will witness the outcome. With nearly 30 halvings still ahead, the current subsidy continues to dominate miner revenue for decades. The debate carries no immediate deadline and centers on a design choice whose practical test lies more than a century in the future.

For the present, Bitcoin’s fixed supply schedule stands unchanged. The exchange between Todd and Back has simply restated the tension between absolute scarcity and the long-term economics of network security.