Zcash Activates NU7 Upgrade, Locking About $16 Million in Sprout

Zcash has activated its NU7 network upgrade, making roughly 12,226 Zcash (ZEC) held in the Sprout privacy pool unspendable under current rules and putting about $16 million beyond holders’ reach.

NU7 rejects version 4 transactions, the only format that can spend coins in Sprout, Zcash’s oldest privacy pool. A valid private key alone will not let owners move the remaining ZEC under the updated rules. Owners needed to move funds out of Sprout before activation to keep them spendable.

Sprout held about 12,226 ZEC as of Thursday morning. At $1,300 per coin, that balance was worth about $16 million.

ZIP 2003 leaves open a possible path to restore access through a future upgrade, but warns that the ability to send Sprout funds may never return. NU7 also shortens the target block time from 75 seconds to 25 seconds. Activation had been expected around 9:30 p.m. ET Thursday at block 3,543,405.