Zcash Loses Over Half Its Value After Disclosed Orchard Counterfeiting Bug

Market Reaction

Sources differ on the size of the drop. CryptoSlate reported that ZEC fell more than 50% to as low as $255 before recovering to about $321, and that market capitalization fell from roughly $10 billion to about $4.5 billion before rebounding to $5.3 billion at press time. Crypto Briefing put the low near $265 and described a 40% decline over 24 hours to $320, citing CoinGecko data. CryptoPotato, which measured the move on June 5, 2026, reported a drop of roughly 45% from above $600 to around $300 within hours. The accounts agree on a selloff of roughly 40% to over 50% and a trough in the mid-$250s to mid-$300s, but differ on starting prices and percentages, likely reflecting different measurement windows.

The selloff deepened after BitMEX founder Arthur Hayes said he had fully exited his ZEC position. Hayes had previously named ZEC, alongside HYPE and NEAR, among his favored assets, and said he had also exited those stakes.

The move reversed a rally that had lifted the token more than 1,000% over the prior year as traders revived a broader bet on financial privacy. Zechub data cited by CryptoSlate indicates that roughly 30% of circulating ZEC, more than 5 million coins, sits in shielded addresses.

Developer Response and Open Questions

Zcash developers say the flaw was patched within days. According to the new disclosure, the bug was remediated through an emergency ecosystem response completed by June 2, 2026, and CryptoPotato reported the same date. The response included a temporary network change that disabled affected Orchard actions, followed by a hard-fork upgrade that restored full functionality, per Crypto Briefing. The bug had been present since Orchard launched in May 2022, a period of about four years that included repeated reviews by cryptographers, engineers and auditors.

Shielded Labs is proposing a network upgrade that would add a new shielded pool with turnstile accounting, a checkpoint designed to reveal any excess supply in Orchard. The team has said a detailed proposal will follow within a week and would need to pass standard governance. It is also hiring a Head of Security and a cryptographer and has started work on formal mathematical verification of the Orchard circuit.

The central question for investors is how much assurance markets require from a system designed to hide amounts and wallet histories. Developers argue that the absence of evidence of exploitation is not evidence that none occurred, and that the rapid patch and disclosure limit ongoing risk. Whether the turnstile proposal and formal verification restore confidence will depend on technical details the team has yet to publish.

Why It Matters

Zcash's maximum supply is 21 million ZEC, so the disclosure goes to the core of what the coin promises. The episode also shows how the privacy design that protects users limits what the network can prove about its own history.