Zcash activated NU6 as its second halving cut issuance in half

Zcash activated Network Upgrade 6 at mainnet block 2,726,400 on November 23, 2024, at 11:02:59 UTC. The consensus change coincided with the network’s second block-subsidy halving, cutting total new issuance per block from 3.125 ZEC to 1.5625 ZEC and replacing the previous development-funding streams with a grant allocation and a protocol-tracked lockbox.

The event mattered beyond a scheduled scarcity milestone. It changed, at one block-height boundary, both the economics of proof-of-work mining and the mechanism through which newly issued ZEC supported protocol development. It also required participating nodes to follow the NU6 rules to remain on the upgraded chain.

The halving cut two related figures

“Block subsidy” and “miner reward” described different quantities on November 23. The protocol-level subsidy fell from 3.125 ZEC to 1.5625 ZEC. Because 20% of the subsidy continued to be reserved for development funding, the miner portion fell from 2.5 ZEC to 1.25 ZEC. F2Pool’s November 19 notice used the miner figure when warning customers that mining revenue would be affected.

That distinction reconciles figures that otherwise appear inconsistent. After activation, 80% of each 1.5625-ZEC subsidy—1.25 ZEC—was available to the miner. Eight percent, or 0.125 ZEC, was assigned for Zcash Community Grants, and 12%, or 0.1875 ZEC, accrued to the lockbox. The per-block amounts are Coinburn calculations from the final percentage allocation; actual miner receipts could also include transaction fees.

The halving reduced the protocol’s issuance rate, but it did not prove that ZEC’s market price would rise or that mining would remain equally profitable. Revenue also depended on ZEC price, network difficulty, a miner’s share of computation, fees and operating costs.

NU6 rewired development funding

Before block 2,726,400, the protocol’s development fund directed 7% of the subsidy to the Bootstrap Project, 5% to the Zcash Foundation and 8% to Major Grants. NU6 ended those streams and implemented the final ZIP 1015 structure for the next block-height interval.

Under the new rules, 8% went to the Financial Privacy Foundation for the express use of the Zcash Community Grants committee. Another 12% was recorded in an in-protocol deferred pool called the lockbox.

The lockbox was deliberately incomplete as a spending system. ZIP 1015 said no disbursement mechanism had yet been defined; a later ZIP and another consensus decision would be needed before those deferred funds could be made available. On November 23, that made the lockbox an accounting commitment under network rules, not a treasury account from which an organization could already withdraw.

The change therefore reduced direct, hard-coded funding of named organizations while preserving a 20% development share. Whether that design would produce more decentralized or effective funding remained an open governance question, not an event-day fact.

A consensus upgrade, not only monetary policy

NU6 also deployed an exact-balance rule for blocks. Zcash’s official upgrade record described the change as requiring coinbase transactions to collect the full miner subsidy and transaction fees. The release path mattered operationally: Zcashd 6.0.0 and Zebra 2.0.1 had shipped mainnet support before the activation height, giving node operators time to upgrade.

The verified November 23 result is narrow but consequential. Zcash’s mainnet crossed the specified height, halved issuance and began enforcing a new funding split. The primary records establish the activation block, timestamp and consensus allocations. They do not establish a causal price response, a measured change in hash rate, or the eventual use of lockbox funds.