Auction-Based Self-Custodial Bitcoin Staking

PoX-6 is the next upgrade to Bitcoin staking on Stacks. It replaces today’s managed allocation of self-custodial staking capacity with an open auction: any participant who sources STX can bid for capacity, and the market, rather than a whitelist, decides who stakes BTC on the Bitcoin L1 and earns BTC. In 2027, the open auction will let anyone stake BTC in the self-custodial path.

Everything here is in research and development, not a commitment from core engineers. Scope can change, and the final design is set through the community SIP (Stacks Improvement Proposal) process before activation. The Genesis Bond (230 BTC) and Bond 2 (505 BTC) are the production data the research draws on.

What changes in PoX-6

During the bootstrap phase, self-custodial Bitcoin staking is whitelisted for anchor participants, and each bonding period’s capacity is allocated to the participants that grow the Bitcoin economy on Stacks (with the Stacks Endowment setting the rate and sizing the period). That let institutions run the product firsthand at small scale: 735 BTC staked across two bonds, with UTXO Management, Sypher Capital, 21Shares and HashKey among the first in.

PoX-6 removes the allocation step. Capacity is sold at auction instead of assigned, so bids rather than a review decide who stakes self-custodially. The whitelist and the application process belong to the bootstrap phase and are not in the design under study.

Two more properties are built in. Each position’s STX-to-BTC ratio locks at a fixed Bitcoin block height, so its terms are deterministic and anyone reading the chain can verify them. And pooling moves to the protocol level, covered below.

How the auction would work

The design follows the model of US Treasury auctions. Institutions bid competitively for staking capacity, the auction clears at a single rate, and individuals who do not bid directly take part at the clearing rate through pooled products from wallets and exchanges. A bidder sources STX, bids for capacity in a bonding period, and if the bid clears, locks that STX beside the BTC they stake for the term.

Three parts of the design are not in question. Bidders compete for capacity, meaning the STX that has to be paired with each staked BTC for it to earn. Results publish at a fixed Bitcoin block height, so anyone can verify a position’s terms.

Frequently asked questions

When does PoX-6 activate? In 2027, the open auction will let anyone stake BTC in the self-custodial path. The activation height is set through the SIP process; no date is confirmed. PoX-5, the current version, activated at Bitcoin block 960,230 on July 30, 2026.

Is PoX-6 confirmed? No. Every feature here is in research and development, not a commitment from core engineers. The community sets the final design through a SIP before activation.

Do I still need to be whitelisted to stake BTC self-custodially? During the bootstrap phase, yes. PoX-6 is designed to replace the whitelist with an auction open to anyone who sources STX.

Does the auction change where my BTC is held? No. In the self-custodial path, BTC stays timelocked on Bitcoin under your custody. Pooled positions run through a pox and sBTC and are not self-custodial.

Can I sell a position before it matures? Early exit and re-entry mechanics are in research, so a holder could sell a position before maturity while the BTC stays in the timelock. This is not available in the current bonding periods.

What does an STX holder get out of PoX-6? STX is what bidders source to win capacity, so demand for Bitcoin yield is demand for STX. A leasing model under exploration would also let STX holders earn a share of BTC yield by providing capacity to Bitcoin stakers.