Bitcoin 21M cap debate erupts after StarkWare CEO’s 4% proposal

StarkWare CEO Eli Ben-Sasson has revived debate over Bitcoin’s fixed supply after suggesting annual issuance.

In a Tuesday post on X, Ben-Sasson said Bitcoin’s 21 million supply cap “doesn’t make sense” because users lose private keys over time. He argued that lost keys reduce the amount of usable Bitcoin and that, over a long enough period, more coins will become unreachable.

Ben-Sasson proposed replacing the fixed cap with a hard issuance rule of up to 4% per year. He said the figure roughly matches global population growth, while still keeping Bitcoin scarce under a known monetary rule.

Lost keys drive the argument

Bitcoin does not have a password reset system. When a holder loses a private key, the coins remain on-chain but cannot be spent. That is why lost Bitcoin can reduce the supply available to buyers and sellers.

Ledger estimated that 2.3 million to 3.7 million BTC are permanently lost, while some reports place the figure near 4 million BTC. Ben-Sasson used this trend to argue that a fixed cap could make Bitcoin less useful over very long periods.

His view runs against a core Bitcoin belief. Many Bitcoin supporters see lost coins as part of the asset’s scarcity, not a problem to fix. The old Bitcoin view is that lost coins act like a “donation” to other holders because the remaining supply becomes harder to buy.

Bitcoiners reject 4% inflation

The proposal drew fast pushback from Bitcoin users on X. Critics said Bitcoin’s 21 million limit is one of its main features and that changing it would make BTC look more like other crypto assets.

Some users also pointed to Bitcoin’s divisibility. Bitcoin can be split into 2.1 quadrillion satoshis, giving users small enough units for payments even if whole BTC becomes harder to access.

Ben-Sasson pushed back, saying those satoshis would also trend toward zero over time if private keys keep getting lost. He said Bitcoin could still remain scarce if the inflation rate stayed fixed and predictable.

The debate links back to comments from Strategy executive chairman Michael Saylor. Saylor spoke about burning Bitcoin private keys as a “pro rata contribution” to other holders, though the report said he did not directly promise to do so himself.

Zcash model enters the debate

Zcash founder Bryce “Zooko” Wilcox suggested another path. He pointed to Zcash’s proposed Network Sustainability Mechanism, which would let users burn ZEC and gradually reissue those coins as future rewards without raising the 21 million cap.

That model tries to help miner incentives while keeping the fixed supply rule. It differs from Ben-Sasson’s proposal because it does not create a higher lifetime limit.

Any change to Bitcoin’s cap would face a high bar. Developers can propose code changes, but node operators, miners, exchanges, wallets, and users would need broad agreement before the network accepts them.

As previously reported by crypto.news, StarkWare has already worked on ways to bring scaling tools to Bitcoin without forking Starknet or launching a new Bitcoin token. This new debate moves from scaling into monetary policy, where Bitcoin users have shown little interest in changing the current supply rule.