Zcash's NU7 network upgrade went live on the protocol's testnet on October 4, triggering at block 4,465,026 and clearing a key milestone ahead of an anticipated mainnet launch in November. The upgrade introduces some of the most significant changes to Zcash in recent years, including a substantially shorter target block interval and a new mechanism that channels transaction fees into future block rewards.

The testnet activation arrives amid renewed market pressure on ZEC. Grayscale's ZCSH spot ETF recorded net outflows of $93.56 million in the week ending October 2 — its first week of withdrawals since late August, according to Tron Weekly's earlier coverage.

What Happened With the Zcash NU7 Upgrade?

The NU7 upgrade activated on Zcash's testnet on October 4, giving users and developers the opportunity to exercise the proposed protocol changes in a live environment before they reach the main network.

According to ZecBlock, a block explorer for the Zcash testnet, block 4,465,026 was mined at 18:21:45 UTC, marking NU7's scheduled activation time. Zcash confirmed the activation in a post on X.

Testnet deployment allows developers to observe how the network performs under the new rules ahead of mainnet activation. The Zcash Foundation has called on test operators to run the release candidate and put NU7 through practical testing, and the activation was also discussed on the Zcash community forum.

The step is significant because the mainnet activation will depend on what developers learn from the testnet phase. Any technical issues that surface could force a revision to the activation timeline.

What Does the NU7 Upgrade Change?

One of the headline modifications in NU7 is a reduction in the network's target block interval. Zcash is currently designed to produce a new block every 75 seconds; under NU7, that target falls to 25 seconds. In practical terms, the new cadence would have the network aiming to produce roughly three times as many blocks per hour as it does today.

The shorter interval is expected to lower the average time it takes for transactions to be confirmed by the network, making Zcash payments faster for the people who use them.

Faster blocks are only one part of the protocol update, however. The other concerns how transaction fees participate in future rewards.

A central feature of the upgrade is the Sustainability Network Mechanism, under which a portion of transaction fees will be directed toward future block rewards. The mechanism was introduced as an additional way to finance block rewards while retaining Zcash's maximum supply model. It could prove essential to the network's further development, as transaction fees would serve as a supplementary component of the reward system alongside existing issuance.

NU7 also updates the list of transaction versions that can be included in blocks. Once the upgrade activates on mainnet, version 4 transactions will cease to be valid.

That change carries direct consequences for funds held in the Sprout shielded pool, because spending them requires the older transaction type. Users who store ZEC in the Sprout pool will therefore need to transfer their assets before NU7 activates on mainnet; otherwise, their funds could become locked under the new network conditions. With mainnet activation presently targeted for November 5 and the activation height to be fixed at the October 20 decision, the current schedule gives Sprout holders a defined window to move their funds — a window that would shift if the timeline changes.

When Could NU7 Reach Mainnet?

Zcash's developers are expected to use the testnet period to examine the upgrade and then decide on mainnet activation. Under the current schedule, October 20 is set as the date for the final decision and the determination of the activation height. Mainnet activation is presently targeted for November 5.

Both dates hinge on the outcome of testing. If issues emerge that require further work, the schedule may be altered.

For now, the testnet activation can be viewed as the next step toward NU7's implementation on the Zcash mainnet.

ZEC Faces ETF Outflows During Upgrade Testing

NU7's testnet debut comes as ZEC weathers a period of weak market performance. Grayscale's ZCSH spot ETF saw net outflows of roughly $93.56 million in the week that ended October 2 — the fund's first negative week since late August, when it had been posting positive flows.

The outflows coincided with a pullback in ZEC's price. After climbing above $1,650 at the end of September, the token slid toward the $1,300 level amid selling pressure.

The backdrop matters ahead of the network upgrade: Zcash is pushing through major technical changes during a stretch of ETF outflows and a notable price correction.

What Comes Next for Zcash?

The next significant event on the NU7 timeline is the completion of testnet testing and the developers' decision on October 20. If testing concludes successfully, the network would remain on course for the intended November 5 launch date.

Between now and then, network performance and transaction behavior under the new rules will need to be observed. Activity in the Sprout shielded pool is another item to track, since any funds remaining there once version 4 transactions cease to be valid would face the new network conditions. On the market side, ZEC's price action and flows into the ZCSH ETF would continue to be relevant drivers.

This article contains market analysis and price information. These are not guarantees. Crypto markets are volatile. Always DYOR. Not financial advice.