Zcash's NU7 Goes Live and Freezes 12,224 ZEC in the Sprout Pool

Zcash's NU7 upgrade went live at block 3,543,405, mined at 02:34 UTC on Friday. Every estimate attached to the height had said 5 November, and the chain got there a day late. Block spacing now targets 25 seconds, down from 75. The casualty is Sprout, the network's original shielded pool, whose balance can no longer be spent by anyone: the one transaction format that could reach it stopped being valid at that block. ZecStats puts the stranded amount at 12,224.21 ZEC.

The chain is already running at the new speed

The target held faster than the first readings suggested. crypto.news, filing on the morning of activation, found intervals averaging around 39 seconds in the opening hours, and said they would settle as mining difficulty adjusted. They did. By 11:11 UTC on Sunday the ZecStats network page showed an observed block time of 25.1 seconds across the previous day. Difficulty is what moved: 311,763,555 before activation, 93,318,158 by early Sunday. Three times as many blocks means roughly a third of the reward in each, and the per-block subsidy drops to 0.52083333 ZEC from 1.5625. The next halving shifts with it, to block 6,132,390 from 4,406,400, which ZecStats places around late November 2028.

Ten thousand coins left Sprout in the last fortnight

The final count is well under the ones before it. This desk had about 23,000 ZEC in the pool back in September, then Odaily's 22,263 as of 22 October, and noted at the time that the two did not reconcile. The frozen balance is 12,224.21. Subtract the October count and roughly 10,000 ZEC moved out before the block arrived, which is arithmetic on two readings and not a figure any source publishes. The dollar value is unsettled too. Cointelegraph and the syndicated Crypto Breaking copy both say about $15 million, while crypto.news says around $15.3 million. At the $1,292.76 ZecStats showed on Saturday, 12,224.21 ZEC works out nearer $15.8 million. None of the three states the price behind its own number.

Everything in the upgrade is still marked proposed

The specification has not caught up with the running code. ZIP 259, the deployment document, lists NU7's contents as ZIPs 207, 214, 218, 235, 237, 2003 and 2008, and ZecStats shows every one of them carrying the status Proposed. This desk reported in October that the spec still called the activation height undecided while node releases were being cut against it. Three weeks on, nothing has merged. ZIP 2003 is the one Sprout turns on: it invalidates version 4 transactions, and version 4 is the only format that can spend from the pool. Cointelegraph and Crypto Breaking both report that the spec leaves open a later upgrade restoring access, while cautioning that spending may never be re-enabled. ZecStats carries the caution and describes no route back.

"All Mainnet operators MUST upgrade before height 3,543,405 (~Nov 5) to stay on the consensus chain," the Zcash Foundation said in the post ZecStats quotes.

That estimate missed by a day, which is what a date does when it is derived from a block height. Operators had to be on Zebra 7.0.0 or Zakura 1.7.0 and later; zcashd is unsupported, and two older Zebra builds stopped dead at block 3,540,768.

What else changed

Sixty per cent of each block's transaction fees now leave circulation into a protocol-level balance, with miners keeping the other 40. ZIP 237 pays that balance back through mining rewards starting at block 8,939,664, around February 2031. ZecStats had it at 370.3255 ZEC on Sunday morning. The 21 million supply cap is untouched.

How many people are locked out is the thing no source counts. Nothing read for this story gives an address count or a number of parties behind the 12,224.21 ZEC, so Sprout's last holders exist in the record as a balance and nothing else. The pool dates to 2016 and stopped accepting deposits at the Canopy upgrade in 2020, which left six years for anyone inside to leave. The exit closed at 02:34 on Friday morning. Whether it reopens depends on a ZIP that has not been written.