Zcash’s NU7 Leaves Sprout on Ice While 60% of Fees Take a Lap 🔄

Zcash’s NU7 network upgrade activated at block 3,543,405 at 02:34 UTC Friday, retiring the legacy Sprout shielded pool and leaving approximately 12,224 ZEC, worth about $15 million to $16 million, unspendable under the new rules. “NU7 has successfully activated on mainnet. A new era of Zcash is here. $ZEC pic.twitter.com/rPaSFe9h7j — Zcash 🛡️ (@Zcash) November 6, 2026,” the project’s official account tweeted. The stranded coins have not been burned and will count toward Zcash’s circulating issuance, but a future upgrade could restore access. ZIP 2003 warns that “the ability to spend Sprout funds may never be re-enabled.”

Sprout launched with Zcash in October 2016 as its original privacy pool, using zero-knowledge proofs to verify transactions without revealing the addresses or amounts involved. NU7 rejects version 4 transactions, the only format capable of spending Sprout funds, meaning holders must use a compatible withdrawal mechanism before activation to avoid losing access even if they retain their passwords and private keys. Sprout addresses begin with “zc,” which can help users identify affected wallet records. Approximately 12,226 $ZEC remained on Thursday morning, down from roughly 22,263 a week earlier; about 9,094 $ZEC departed Sunday and another 40 $ZEC followed Wednesday. At $1,300 per $ZEC, the balance represented about $16 million before further withdrawals reduced the amount.

The upgrade also introduces the Network Sustainability Mechanism, which removes 60% of transaction fees from circulation and gradually reissues them through future mining rewards as block subsidies decline. Reissuance is scheduled to begin around February 2031, with the recycled funds distributed along a smooth curve above the existing halving schedule. Zcash’s 21 million ZEC supply cap and halving schedule remain intact. “This is a huge milestone for Shielded Labs,” Jason McGee of Shielded Labs, the Zcash development organization behind the mechanism, tweeted on November 5, 2026. The NSM was Shielded Labs’ first project and builds on an idea developer Nate Wilcox originally called the Zcash Posterity Fund. A separate proposal under consideration would require Zcash Community Grants to contribute 50,000 ZEC from its treasury to the NSM.

NU7 cuts Zcash’s target block interval from 75 seconds to 25 seconds, reducing the expected wait for transaction confirmations. In a stress test of 80 nodes across 11 regions using blocks filled with private transactions, Zakura developers measured an orphan rate of 3.43% at 25-second blocks and 1.57% at 75-second blocks. They expect the live network’s rate to remain under 1% because mining is more concentrated and blocks are less full. The upgrade also limits how much private transaction activity can fit into each block, reducing the amount of data wallets must scan to locate their payments.