A call has emerged to review Bitcoin’s 21 million BTC supply cap over the long term. As more Bitcoin is lost when people misplace private keys, the amount actually available to trade could keep shrinking over time, prompting arguments for a new monetary policy rather than an absolute supply limit.

According to blockchain outlet U.Today on July 8, Zcash co-founder Eli Ben-Sasson (일라이 벤 새슨) suggested that Bitcoin’s fixed supply cap may not fit reality over the long term.

Ben-Sasson pointed to the loss of private keys as the biggest problem. Bitcoin’s total issuance is capped at 21 million BTC, but if more coins become inaccessible as keys are lost, the supply circulating in the market could steadily decline, he said. He argued this would be an unavoidable structural problem over the long term.

Bitcoin caps total issuance at 21 million BTC under the monetary policy designed by Satoshi Nakamoto. The core idea is to maintain scarcity rather than increase supply, allowing it to function as a store of value. Ben-Sasson’s proposal is seen as calling for renewed discussion of Bitcoin’s most fundamental principle.

He argued that a new monetary policy with clear issuance rules could be more realistic than maintaining an absolute supply cap. For example, applying an annual issuance rate of up to 4 percent to keep the tradable supply at a certain level could secure market liquidity while preserving predictability in monetary policy, he said.

Even so, such a proposal is unlikely to be reflected in the Bitcoin network. To change Bitcoin’s supply structure, developers would need to prepare relevant improvement proposals, write implementation code, and then win broad agreement from the community, miners and node operators. They would then have to incorporate the changes into Bitcoin Core and go through procedures to activate them on the network.

In particular, changing the supply cap is likely to lead to a hard fork that is not compatible with existing rules. In that case, most network participants would need to accept the new rules, and if consensus is not reached the chain could split.

In the market, the problem of a shrinking effective supply due to lost private keys has been raised for a long time, but there remains strong resistance to changing the 21 million BTC cap, which is Bitcoin’s core value, as a way to address it.

Ultimately, the proposal is meaningful in that it has prompted renewed thinking about the balance between Bitcoin’s scarcity and the decline in its tradable supply. But an assessment has emerged that it is unlikely to lead to changes in the supply structure in practice, given the high consensus hurdles and the conservative nature of the Bitcoin community.