Key facts
- ZecStats data reported by Decrypt put 12,224 ZEC, roughly $15 million to $16 million, in the Sprout pool.
- ZecStats says NU7 makes version-4 transactions invalid, leaving Sprout funds "unspendable: frozen, not burned."
- The report says the upgrade is scheduled for block 3,543,405, with the latest block at publication 3,543,027.
- The Zcash Foundation said NU7 cuts the target block interval from 75 seconds to 25 seconds.
- The report says the coins stay in Zcash's circulating issuance and a later upgrade could theoretically restore access.
Zcash is preparing to deactivate version-4 transactions at block 3,543,405, the network's NU7 upgrade, which would make the approximately 12,224 ZEC still sitting in its original Sprout privacy pool unspendable, according to ZecStats data reported by Decrypt on November 5, 2026. At recent market prices, the report put those holdings at roughly $15 million to $16 million.
ZecStats says in its information card for Sprout that "NU7 (block 3,543,405) makes v4 transactions invalid, so what remains in Sprout is unspendable: frozen, not burned." The upgrade is expected on the evening of November 5 in the United States, but the exact deadline depends on how quickly the blockchain processes new blocks rather than on a set clock time. At the time of publication, the latest available block was 3,543,027.
Sprout was introduced when Zcash launched in 2016 and uses zero-knowledge proofs, which verify a transaction without revealing its details. Sprout has been closed to new deposits for years, but holders could still withdraw funds; NU7 removes the only transaction format capable of moving coins out of the pool. The network's technical specification says transactions using that format will become invalid after activation and warns that spending those funds may never be re-enabled.
According to the report, the coins are not being destroyed: they will continue to count toward Zcash's circulating issuance, and a future upgrade could theoretically restore access, though the report says that is not guaranteed. The blockchain cannot reveal who owns the remaining Sprout balance, so it is unknown how much belongs to active users and how much is already inaccessible because owners lost their keys.
The report says holders using modern supported wallets do not need to migrate coins out of Sprout, though keeping wallet software updated remains important; Sprout addresses begin with "zc." The Zcash Foundation said NU7 also cuts the target block interval from 75 seconds to 25 seconds, so transactions should receive their first confirmation about three times faster.