The Zcash network activated its NU7 upgrade at block height 3,543,405 on November 5, 2026, making the remaining funds in the legacy Sprout privacy pool unspendable. Chain data shows approximately 12,224 ZEC still held in Sprout, Zcash's original shielded pool from the protocol's 2016 launch that was later superseded by Sapling and Orchard — worth roughly $15 million to $16 million at recent ZEC prices around $1,230. Holders retain their private keys, but once the network rejects version-4 transactions, they lose the ability to move those notes.

The activation comes as altcoin markets track privacy-coin developments, including a separate Winklevoss Asset Services Zcash ETF filing track. Clock-based estimates placed activation near 9:30 p.m. Eastern, though the network rule triggers at the block height itself, not the clock.

How the Zcash NU7 Upgrade Locks Sprout Funds

Per ZIP 2003 and ZIP 259, NU7 disallows all version-4 transactions. Sprout transfers exist only in that format, and the newer v5 and v6 transaction formats do not carry Sprout spends. Because Sprout predates those formats, its notes were never given a representation in the transaction versions the network now accepts. As a result, leftover Sprout notes cannot move after activation.

The ban applies network-wide and is not a wallet setting users can opt out of. Consensus rules bind every node identically, so no intermediary can approve a Sprout spend on a holder's behalf. Private keys alone do not restore spending once consensus rejects v4 transactions. Sapling, Orchard, and transparent ZEC held outside Sprout remain spendable under the supported formats.

ZIP 2003 does not burn or unissue the Sprout balance. The coins remain counted as issued supply, and a later upgrade could theoretically restore a spend path — though the ZIP also states that path may never return. Holders should therefore treat remaining Sprout funds as practically locked once NU7 activates.

Faster Blocks and New Fee Rules Under NU7

NU7 also cuts the target block interval from 75 seconds to 25 seconds, meaning blocks arrive about three times faster. Three confirmations now drop from roughly 3.75 minutes to about 75 seconds.

The 21 million ZEC supply cap and the four-year halving schedule remain in place. Per-block subsidy falls because blocks come more frequently, while daily issuance stays broadly stable.

ZIP 235, deployed with NU7 per ZIP 259, routes 60% of transaction fees out of circulation into the Network Sustainability Mechanism (NSM), with miners keeping the remaining 40%. Planned NSM reissuance sits near height 8,939,664 — around 2031 on the mainnet schedule.

The headline stake remains the Sprout pool: about 12,224 ZEC becomes unspendable at activation unless a future consensus change reopens a spend path. Everyone else keeps normal access to non-Sprout balances.