A first briefing · Genesis Bond / PoX-5
Stacks Bitcoin Staking lets you lock bitcoin on Bitcoin itself, pair it with a smaller STX lock on Stacks, and sit first in line for miner bitcoin already being spent to produce Stacks blocks. The structure is called a protocol bond. The first institutional run is the Genesis Bond.
If you have never heard of Stacks, start here. Every term is defined the first time it appears.
Stacks is a blockchain that settles to Bitcoin. It does not try to replace Bitcoin. Its native token is STX. Since 2021, Stacks has used a consensus mechanism called Proof of Transfer (PoX): people who want to produce Stacks blocks (miners) bid real bitcoin. That bitcoin is not burned. It is transferred to participants who help secure Stacks. Historically, that flow has distributed thousands of BTC.
A protocol bond is a dual lock. You lock bitcoin on Bitcoin Layer 1 (the main Bitcoin chain) and you lock a smaller amount of STX on Stacks. In return, you are first in line for a slice of the bitcoin miners are already paying. Yield is paid in bitcoin.
This is not lending. On the self-custodial path there is no borrower holding your BTC, no wrap, and no bridge. Your coins stay in a standard Bitcoin timelock under keys you control. The STX sleeve is “staking capacity”: it qualifies the bond. It does not earn the bond’s BTC yield.
The first institutional program using this design is the Genesis Bond, live under the current rule set called PoX-5 (Stacks Improvement Proposal 045). A later upgrade, PoX-6, is expected to make participation permissionless.
Six steps, in order. The concrete dollars and bitcoin amounts are in the worked example.
You create a standard Bitcoin output (a UTXO — one discrete chunk of unspent bitcoin) that cannot be spent until a future block. The opcode is OP_CHECKLOCKTIMEVERIFY (CLTV). The coins stay on Bitcoin under your keys. They are not wrapped and not bridged on the self-custodial path.
On Stacks you lock STX equal to roughly 5% of the bitcoin’s dollar value. That STX is staking capacity. It qualifies the bond. It does not receive the bond’s BTC yield. Its dollar value can move while it is locked — that is a real risk, covered below.
The bonding period is about 6 months, or 25,200 Bitcoin blocks. Rewards are designed to pay out about weekly — 24 payouts over the term.
During bootstrap, the target is about 3% BTC APY, measured on a 52,560-block Bitcoin year. One 6-month bond therefore delivers roughly 1.44% of locked BTC in total if the target is met — about half of 3%.
At maturity, BTC unlocks. The BTC timelock actually expires about 10 days before period end so you can re-lock into the next period if you want. STX unlocks at term end. There is no slashing: principal is designed to return in full. (STX’s price can still have changed.)
You can reclaim BTC before maturity. Remaining undistributed yield is forfeited. The STX sleeve stays locked for the full term either way.
Snapshot of the Genesis Bond as reported in September 2026. Two primary sources disagree slightly on enrolled BTC. Both are shown.
Start
966,350
Bitcoin block, reward cycle 143 · about Sep 10, 2026
Enrolled BTC
230 / 250
Muneeb Ali vs Stacks blog — see note
First rewards
Sep 17
Weekly automated BTC payments thereafter
Next window
Oct 10
Larger capacity expected · ~monthly periods
Demand sold out. About 230 BTC enrolled, with roughly 11.5 BTC-worth of STX locked for the bonds (that is the 5% sleeve). About 20 million additional STX locked versus the prior cycle. Weekly automated BTC payments. Next bond around October 10, with larger capacity expected.
250 BTC bonded. Named participants: 21Shares, HashKey Cloud, UTXO Management (Nakamoto), and Sypher Capital (via StackingDAO). First rewards expected September 17.
Same numbers throughout the page so risks stay comparable. Prices are illustrative, not a forecast.
Key number
If the 3% target holds, one 6-month bond on 1 BTC pays about 0.0144 BTC (~$1,440), in ~24 weekly slices of 0.0006 BTC (~$60). You also lock about $5,000 of STX.
| Item | Amount | How it is derived |
|---|---|---|
| BTC locked | 1.0000 BTC | Your principal on Bitcoin L1, timelocked |
| Assumed BTC price | $100,000 | Round number for the briefing |
| STX sleeve | $5,000 of STX | 5% × $100,000. Quantity of STX depends on the STX price that day |
| Target APY | 3.00% BTC | Bootstrap target, 52,560-block Bitcoin year |
| Term yield if target holds | 0.0144 BTC · $1,440 | ~Half a year of 3% → 1.44% × 1 BTC |
| Weekly slice (24 payouts) | 0.0006 BTC · $60 | 0.0144 ÷ 24 |
| At maturity | 1 BTC back + paid yield | STX unlocks too. Its dollar value may have changed. No slashing of BTC principal by design |
You do not get 3% in six months. You get about half of that if the target holds, because the bond is half a Bitcoin year. The STX never “earns the 3%.” The 3% is a bitcoin yield on the bitcoin lock.
Miners already bid BTC to produce Stacks blocks. That BTC fills a reward pool each roughly weekly cycle. Protocol bonds do not invent a new borrower. They sit at the top of an existing waterfall.
Paid at the bond’s target rate, before anyone else.
Proposed share: about 85% of the remainder after bonds are paid.
Stores surplus to cover later shortfalls.
Coverage ratio = reward pool ÷ bond obligations. The protocol aims for about 2.0× coverage: two dollars of miner BTC for every dollar the bonds are owed that cycle.
If miner bids shrink, STX-only yield compresses first. Bond yield is the last thing to give. If stress continues and the reserve is empty, weekly bond payouts can still miss the target. Principal is still designed to return; the coupon is not guaranteed.
Now · PoX-5
The Stacks Endowment manages capacity and the target rate. Self-custodial participation is whitelisted. New bonding periods are roughly monthly. Launch talk centered on about 3,000 BTC of program capacity and a 3% target.
Next · PoX-6
Expected on a roughly 6–12 month horizon. No whitelist. Rate and access would be set by auction rather than Endowment allocation.
Why it matters
Until PoX-6, who can bond on the self-custodial path, and how large a book the program will take, is a policy decision — not an open market.
Same economic idea, different trust assumptions. Roughly 10% of each period’s capacity is reserved for pools.
You timelock BTC under your own keys. During bootstrap this path is institutional / whitelist. Custody tooling mentioned in the ecosystem: Fireblocks, Fordefi, and Leather + Ledger.
No traditional borrower. No sBTC in the critical path. This is the cleaner instrument to model if you can get capacity.
Open through pools such as StackingDAO, Fast Pool, and Xverse. This path uses sBTC (a Stacks representation of bitcoin, secured by a signer set) plus a pool/operator. You inherit those trust assumptions. Fees mean net yield is often below the headline 3%.
Keep the 1 BTC / $100,000 / $5,000 STX sleeve / $1,440 target-yield example in your head. That is the baseline “good case” coupon.
Your BTC is timelocked. You can reclaim it early, but you give up yield that has not been paid yet. STX stays locked either way.
Miner bids can fall. The reserve can be exhausted. Weekly payouts can then print below plan. BTC principal is still designed to return in full.
You must hold STX for the term. The sleeve is small versus the BTC, but STX is more volatile. A hard dump can erase the bitcoin yield in dollar terms.
BTC staking demand, STX demand and price, miner profitability, and the ability to pay bond yields all feed one another.
The Bitcoin L1 timelock is a standard script. The Stacks-side distribution logic, and especially sBTC and pooled paths, are newer. New code can fail in ways a CLTV UTXO does not.
Until PoX-6, capacity and the whitelist are controlled by the Endowment. You can understand the bond and still be unable to buy the clean version of it.
Not self-custodial. You rely on sBTC signers and the pool operator. Fees sit between you and the headline rate.
These are the features that make the instrument worth studying. They are not a recommendation to buy it.
On the L1 path, yield is paid in bitcoin and principal stays in a Bitcoin timelock you control.
You are not handing BTC to a borrower. You are inserting yourself at the top of a miner-paid waterfall that has been live since 2021.
Bonds are tranche 1. STX-only stakers and the reserve absorb stress first.
Capacity is sized to defend the target (talk of ~3,000 BTC and ~2.0× coverage). That is a policy choice, not a law of nature, and it goes away in a permissionless auction.
Bonding pulls STX out of circulation for the term. Genesis reportedly added ~20M STX locked versus the prior cycle, plus the ~11.5 BTC-worth sleeve on the bonds themselves.
There is a stated path toward borrowing against staked BTC. Muneeb Ali has called this a “fed rate for bitcoin.” That is his claim, not a fact — useful as a framing, not as a description of what exists today.