The Stacks PoX-5 Hardfork Is Live: What Comes Next

Stacks has activated the PoX-5 hardfork, the consensus upgrade that lays the foundation for Bitcoin Staking. Activation completed at Bitcoin block 960,230 on Thursday, July 30, and core contributors have verified the network is operating under the new rules. PoX-5 is the first of the Satoshi Upgrades, a series of protocol releases with more details following later in August.

The hardfork went as planned. The PoX-5 codebase was audited by Trail of Bits and Clarity Alliance, with additional review by security partner Asymmetric Research. Miners upgraded and signers met the approval threshold ahead of activation, tracked live on public dashboards, and block production continued through the transition. This blog post covers what the hardfork changed, what STX holders and stakers need to do now, and the Bitcoin Staking rollout ahead.

What PoX-5 Changed

PoX-5 upgrades Proof of Transfer, the Stacks consensus mechanism where miners spend BTC to mine Stacks blocks. In practical terms, the upgrade does three things:

• Introduces Bitcoin Bonds, which let holders pair BTC on Bitcoin L1 with STX on Stacks to earn self-custodial BTC yield without leaving Bitcoin
• Improves the consensus mechanism with functional and quality-of-life updates, including staking without cooldown cycles and streamlined pool participation
• Keeps BTC rewards flowing to STX-only stakers, who continue earning by staking STX alone

Bitcoin Bonds are now active at the consensus level and open for participation in phases. During the bootstrap period, bond capacity is allocated to whitelisted participants, starting with an institutional Genesis Bond expected in late August. Community participation runs through selected staking pools using sBTC as capacity scales. The full design is detailed in the Bitcoin Staking whitepaper.

If You Stake STX: It’s Time To Restake

Every staker needs to restake to keep earning rewards. The hardfork moved staking from the previous contract to the new PoX-5 contract, and following the precedent set by prior PoX upgrades, all previously staked STX unlocked at activation. Restake before block 962,050 to earn from the first PoX-5 cycle. Rewards from the final pre-fork cycle pay out normally.

Timing depends on how you stake. Solo stakers can restake now. Pool participants restake once their pool provider has updated for PoX-5, which can take longer, so check your pool provider's announcements for their reopening schedule.

Restaking also comes with upgrades. PoX-5 removes the cooldown cycle, so stakers can change their reward address without missing a cycle, and streamlines pooled staking so pool participants are less exposed to missed commitments. A step-by-step restaking guide and video walkthrough will be published on Friday.

If You Hold STX

STX balances, wallet addresses, and keys are unaffected. The hardfork created no new token, requires no swap or migration, and changes nothing about how STX is held. Holders who are not staking do not need to do anything.

BTC Rewards Under PoX-5

Stakers who restake continue automatically earning BTC yield on Stacks under the new consensus model, exactly as they did before the fork. Reward distribution changes as follows: any bonded BTC positions locked alongside STX receive a fixed target yield first, and everything beyond those obligations splits 85% to STX-only stakers and 15% to a reserve fund that buffers future payouts. With minimal bonded capacity in the first cycles, STX-only stakers receive most of the BTC rewards in this early phase. The full waterfall distribution mechanism is detailed in the Bitcoin Staking whitepaper.

If You Hold STX on an Exchange

Exchanges paused STX deposits and withdrawals around activation, standard procedure for blockchain hardfork transitions and the same as every previous Stacks upgrade. Trading typically continued without interruption. Deposits and withdrawals reopen once each exchange confirms the upgraded network is stable, usually within hours, and each exchange communicates its own window through its own announcements. Exchanges handle all technical steps for the STX held on their platforms.

Network Status

Block production continued while the network transitioned to PoX-5 rules, and sBTC deposits and withdrawals operated normally through the upgrade. Node operators still running older software must upgrade to stacks-core 4.0.1 to stay on the network. Network health data will follow in the days ahead on official Stacks channels.

What Comes Next

PoX-5 activation opens the Bitcoin Staking rollout: restaking under the new contract this week, the institutional Genesis Bond in late August, and bonding capacity scaling through the months after. More details on the Satoshi Upgrades, the series of protocol releases that PoX-5 begins, follow later in August. Every milestone will be announced on official Stacks channels as it clears. Stacks is growing Bitcoin, and the rails are now switched on.

Every milestone will be announced as it clears. Stay up to date on the Bitcoin Staking roadmap.