Zcash (ZEC) NU7 Upgrade to Freeze $16M Left in Sprout Pool

By Nodora News · 5 November 2026

Zcash (ZEC) NU7 upgrade will make about 12,226 ZEC, worth roughly $16 million, still in the old Sprout privacy pool unspendable. Here's what holders need to know.

Zcash (ZEC) holders who still keep coins in the network's original Sprout privacy pool are running out of time. The NU7 network upgrade, set to activate at block 3,543,405, will stop the network from accepting the only transaction type that can spend Sprout funds. About 12,226 ZEC, worth roughly $16 million at current prices, was still sitting in the pool on Thursday, November 5, and anything left there after activation becomes unspendable, even for owners who hold valid private keys.

Key takeaways

• NU7 disables version 4 (v4) transactions, the only format that can move coins out of Sprout.
• About 12,226 ZEC (~$16 million) remained in Sprout on Thursday morning, down from roughly 22,263 ZEC a week earlier.
• Activation is expected around 02:30 UTC on Friday, November 6 (late Thursday evening in New York), depending on block times.
• The coins are not burned and stay in Zcash's supply, but there is no promise access will ever be restored.
• NU7 also cuts Zcash's target block time from 75 seconds to 25 seconds.

What is the Zcash Sprout pool and why is it closing?

Zcash lets users hide the sender, receiver and amount of a payment. Those private balances live in "shielded pools", which are separate sections of the ledger, each built on a different generation of privacy technology.

Sprout was the first one. It launched with the network in October 2016 and was a landmark at the time, the first large-scale use of general-purpose zero-knowledge proofs (a way to prove a transaction is valid without revealing its details). But Sprout was slow and memory-hungry, and it was soon replaced by the newer Sapling and Orchard pools, which are faster and add features such as viewing keys.

Today Sprout is barely used, yet every Zcash node still has to carry the code that checks it. ZIP 2003, the formal proposal behind this change, says that legacy code adds complexity and potential denial-of-service risk to the software that validates blocks, with little reason for developers to keep optimising it. Removing v4 transactions shrinks that attack surface.

How much ZEC is at risk, and is it being burned?

According to ZecStats figures cited by CoinDesk, the Sprout pool held about 22,263 ZEC a week ago. Holders have been moving out quickly since then:

• Sunday: about 9,094 ZEC left the pool in a single day.
• Wednesday: only around 40 ZEC moved out.
• Thursday morning: about 12,226 ZEC remained, roughly $16 million at a ZEC price near $1,300.

The slowdown matters. It suggests that most active holders have already migrated, and that a large share of what is left may sit in wallets whose owners have lost their keys, forgotten about them, or simply aren't following the news. The public pool balance can't show who owns the coins, so nobody can say for sure how much is truly abandoned.

The coins are not being burned or confiscated. ZIP 2003 keeps them counted in Zcash's issued supply and leaves open the theoretical option of a future upgrade that restores access. It is also clear that spending Sprout funds "may never be re-enabled", so holders shouldn't count on a rescue.

When does NU7 activate?

NU7 is tied to block height 3,543,405 rather than a fixed clock time. Blockchair data showed the chain at about block 3,542,506 at 07:47 UTC on Thursday, leaving around 900 blocks to go. At the current 75-second target, that points to activation around 02:30 UTC on Friday, November 6, which is late Thursday evening in New York and the middle of the day in Asia and Australia. Faster or slower block production by miners could move that by an hour or so.

Anyone with old Zcash wallets can check quickly: Sprout addresses start with "zc". If funds sit at such an address, they need to be moved to a supported Sapling or Orchard address before the activation block. Coins in the newer pools and in transparent addresses are not affected by the Sprout cut-off.

ZEC price and market reaction

The deadline lands during a strong week for ZEC. The token jumped about 14% on Wednesday as traders positioned ahead of the upgrade (we covered that move in Zcash (ZEC) Jumps 14% Ahead of NU7 Upgrade to 25-Second Blocks), and it led the large-cap rebound again on Thursday after the U.S. midterm results lifted risk appetite.

OKX prices at the time of writing:

• ZEC: about $1,322, up roughly 3% in 24 hours (24-hour range $1,271 to $1,352).
• BTC: about $80,390, up roughly 2.7%.
• ETH: about $2,414, up roughly 4.5%.

At around $1,320 per coin, the remaining Sprout balance is roughly 0.07% of ZEC's total market value, so the freeze is unlikely to move the price on its own. Its bigger significance is for individual long-term holders, and as a rare example of a major blockchain retiring a pool that still holds real money.

You can follow ZEC alongside other major coins on Nodora Charts.

What to watch next

• Last-minute migrations. Watch the Sprout pool balance on trackers such as ZecStats in the final hours. Any further outflows will lower the amount that ends up frozen.
• Activation itself. NU7 also cuts the target time between blocks from 75 to 25 seconds, so exchanges may briefly pause ZEC deposits and withdrawals while they upgrade nodes. Check your exchange's notices before moving funds.
• Faster confirmations. Once live, shorter blocks should mean deposits get credited sooner, one of the main selling points of the upgrade.
• Any recovery debate. If a large balance is left behind, the community may later discuss whether a future upgrade should reopen a path for Sprout coins, as ZIP 2003 allows in theory.

Zcash isn't the only network weighing a hard choice at the protocol level this week; Polygon is also debating a fork to deal with stolen funds, as covered in Polygon (POL) Hard Fork Proposed to Return $6.8M in Stolen Tokens.

This article is for information only and is not financial advice.

#Zcash #ZEC #NU7 #Network Upgrade #Privacy

This article is general information, not financial advice.