Dorsey’s Block adds Bitcoin proof-of-reserves for treasury and apps

Jack Dorsey-led Block launched proof-of-reserves for its 8,883 BTC corporate treasury and for Cash App and Square on Monday in Las Vegas, posting the details to X.

The feature lets anyone verify Block’s Bitcoin balances through on-chain signatures. Block wrote on X that the disclosure covers the BTC recorded on its balance sheet and that “people shouldn’t have to trust that their bitcoin is there, they should be able to verify it.” The company added the reserves are “actively controlled, not just historically observed.”

The 8,883 BTC disclosed by Block is valued at about $681.4 million and ranks as the 14th-largest corporate Bitcoin holding.

At the same event, Block introduced a Bitkey hardware wallet with a touchscreen for transaction verification. Earlier this month, Cash App launched accounts for kids and a feature that will allow certain users to have payments automatically converted into Bitcoin. The company also launched a Square merchant offer providing 5% Bitcoin cash back and raised Bitcoin withdrawal limits to $10,000 per day and $25,000 per week.

Proof-of-reserves became more common after the collapse of FTX in November 2022, and Binance vs OKX is one of the clearest examples of how large exchanges now compete on reserve transparency. Major platforms, including Kraken, Bitfinex and Bitget, have also published proof-of-reserves disclosures.

Strategy, the largest corporate Bitcoin holder, has not published proof-of-reserves. In May 2025, Strategy executive chairman Michael Saylor argued the practice creates security risks, saying “It actually dilutes the security of the issuer, the custodians, the exchanges and the investors,” and calling proof-of-reserves “a bad idea.”

Block is led by Jack Dorsey, who has long promoted wider use of Bitcoin for payments. The company said the proof-of-reserves offers a method for on-chain cryptographic verification but did not disclose further technical details about the signature method.