Bitcoin's 21 Million Supply Cap Debate Reignites: Todd Calls for "Permanent Issuance" vs. Back's "Dangerous Trap"

The long-running debate over Bitcoin's 21 million supply cap has reignited. Bitcoin Core developer Peter Todd argued that a small amount of Bitcoin should be permanently issued to miners even after 2140, while Blockstream CEO Adam Back directly countered, calling it a "dangerous trap dressed in technical logic."

The debate was sparked this week at the Bitcoin++ conference, where Todd's past remarks resurfaced. In his conference speech, Todd argued that a small amount of Bitcoin should be permanently issued to continue compensating miners even after 2140, when the last new Bitcoin is expected to be mined.

The Logic Behind Permanent Issuance

Bitcoin miners currently receive compensation in two ways: block subsidies from newly issued Bitcoin, and transaction fees from transactions included in blocks. Block subsidies are halved approximately every four years through halving events, and by around 2140 they will effectively reach zero. After that point, Bitcoin's network security costs would need to be funded entirely by transaction fees.

Todd's core argument is that transaction fee revenue is too volatile to reliably sustain network security over the long term. If transaction fees spike abnormally in a particular block, miners could have an economic incentive to reorganize the chain and re-mine the fee-rich block rather than continuing to build on the existing chain. A permanent block reward of a certain size would reduce this incentive, according to his reasoning.