Zcash NU7 Goes Live on Testnet With 25-Second Blocks, and…

Zcash NU7 activated on the public testnet at block 4,465,026 on Monday, per CoinDesk, a day ahead of the roughly 6 October the Zcash Foundation had expected. The upgrade cuts target block spacing from 75 seconds to 25, routes 60% of every block's transaction fees into a reserve, and retires the oldest shielded pool on the network.

Developers review the Zcash NU7 testnet run and decide on mainnet activation on 20 October, with 5 November still a target rather than a scheduled date. No mainnet activation height has been set, and ZEC trades at about $1,320 as the tenth-largest cryptocurrency by market value on roughly $22.4 billion of capitalization across 16.97 million coins.

Zcash NU7 Activated at Testnet Block 4,465,026, a Day Early

The Zcash Foundation shipped Zebra 7.0.0-rc.0 on 2 October with the activation height compiled in, telling testnet operators to upgrade before block 4,465,026 to stay on the Zcash NU7 chain. The release notes put activation at "expected around October 6." It came in on the 5th.

Mainnet operators were told to take no action, and that instruction still stands. The 20 October meeting is where the go or no-go call gets made, and a 5 November mainnet target without an activation height attached is a plan rather than a commitment. Holders voted the direction in September, when 99.9% of nearly 2.4 million ZEC backed the move to 25-second blocks and 98.9% voted to keep the bitcoin-style halving schedule.

Investor Takeaway

Blocks Every 25 Seconds, With the Per-Block Reward Divided by Three

ZIP 218 is the change holders will notice. Tripling the block rate takes the network from about 1,152 blocks a day to about 3,456, and every confirmation threshold shortens in proportion. Six confirmations currently take roughly 7.5 minutes and would take about 2.5 under Zcash NU7, which is the number exchanges and payment processors will care about. Ten confirmations fall from 12.5 minutes to a little over four.

Issuance does not change. Zebra triples the remaining halving intervals and divides each scheduled block reward by three, so the daily ZEC emission and the 21 million supply cap stay exactly where they were. On testnet the adjusted third halving sits at block 4,497,948. Faster blocks with identical issuance is the whole design, and it is the part of Zcash NU7 most likely to be misread as an inflation change.

Sixty Percent of Every Block's Fees Leave Circulation Under ZIP 235

The Network Sustainability Mechanism is the second pillar. Under ZIP 235, 60% of each block's transaction fees are removed from circulation and placed in a reserve, and miners keep the other 40%. ZIP 237 governs how that reserve is eventually reissued, and on testnet reissuance begins at block 7,305,222. Zcash NU7 therefore ships the collection mechanism years before the redistribution it funds. Holders approved delaying reissuance until February 2031 by 96.6% in the September vote.

The Zcash NU7 fee reserve only matters at scale. Zcash fees are small, so the reserve builds slowly at current usage, and the argument for it rests on what shielded volume does over years rather than quarters. Shielded transactions reached a four-year high earlier this cycle, which is the usage trend the NSM is built to capture.

Sprout Holders and Exchanges Have Until the 20 October Decision

Zcash NU7 retires the Sprout shielded pool and disables v4 transactions. Anyone still holding ZEC in Sprout, the original 2016 privacy system, needs to migrate before mainnet activation or lose the ability to spend through existing mechanisms. Exchanges and wallet operators need node software that supports Zcash NU7, and the testnet window is when that gets tested rather than discovered. Infrastructure providers were preparing testnet updates from 5 October.

For traders, the upgrade arrives into a cooling tape. ZEC is down 16.8% over the past week and 2.4% on Monday from a $1,352.37 close, though still up 29.1% on the month and 157.7% in 2026 after a rally past $1,200 driven by ETF inflows and short squeezes that also drew $28.7 million of long liquidations in a single 12-hour stretch. F2Pool co-founder Chun Wang argued in September that the rally is a narrative bid rather than a fundamentals story, a view Zcash NU7 either answers with working 25-second blocks on mainnet or does not. The testnet is the first place that gets tested in public.

Investor Takeaway