Stacks vs Rootstock: Bitcoin’s Oldest DeFi Bet in 2026

Two years before Ethereum shipped its first optimistic rollup, and long before anyone talked seriously about running stablecoins on Bitcoin rails, two teams set out to answer the same awkward question: can the most valuable, most conservative blockchain do anything other than sit still? Rootstock went live on 2 January 2018 as a smart-contract sidechain merge-mined by Bitcoin’s own miners, according to research from Spark. Stacks, then called Blockstack, had already done something no crypto project had managed before it, running a token sale that the U.S. Securities and Exchange Commission actually signed off on. In 2026, after the worst year Bitcoin DeFi has had, these two are the oldest survivors of that early bet, and they reached this point by almost opposite routes.

The backdrop is unforgiving. Bitcoin trades near $76,800 with a market capitalization around $1.54 trillion, still roughly 39% below the record $126,080 it set in October 2025, per CoinGecko. Total value locked across Bitcoin DeFi peaked close to $9.1 billion in October 2025 and then fell about 74%, according to Spark research. In September, the Liquid Network, another federated Bitcoin sidechain, lost roughly $320 million in about 35 minutes to a software bug rather than a stolen key, as crypto.news reported. If there was ever a moment to ask which Bitcoin sidechain actually works, and at what cost in trust, it is now.

Rootstock and Stacks are not the names generating the loudest headlines. Attention has drifted to zero-knowledge rollups such as Citrea and to channel-free payment layers such as Ark and Spark. Yet the two veterans still hold most of the genuine, on-chain Bitcoin DeFi that exists today, and the contrast between them is the sharpest lens available on what Bitcoin DeFi can and cannot be. One is a merge-mined copy of the Ethereum Virtual Machine; the other is a separate chain with its own programming language that settles into Bitcoin. One secures its ledger with almost all of Bitcoin’s hashrate; the other pays holders real bitcoin as a reward. Both, crucially, ask you to trust someone else with your BTC while it sits on the sidechain. This is the head-to-head.

Two Roads to Bitcoin DeFi

Bitcoin was designed to be hard to change, which is exactly why building applications on top of it is difficult. Its scripting language is deliberately limited, it has no native concept of a global state machine, and its social consensus resists new features. A sidechain sidesteps all of that. It is a separate blockchain with its own rules and its own block production that pegs to Bitcoin: you lock BTC on the main chain, a representation of it appears on the sidechain, and you can, in theory, redeem it later. The idea traces back to a 2014 paper co-authored by several developers who would go on to found Blockstream, and it spawned an entire family of designs.

Rootstock and Stacks pick opposite ends of that family. Rootstock’s bet is familiarity: take the Ethereum Virtual Machine, the environment where most smart-contract developers already work, and bolt it onto Bitcoin as a sidechain that Bitcoin miners secure for free through merge-mining. A Solidity developer can deploy on Rootstock with minimal changes. Stacks makes the opposite bet: rather than imitate Ethereum, it runs a standalone chain with a purpose-built language called Clarity, and it anchors its history into Bitcoin so that rewriting Stacks would require rewriting Bitcoin. Where Rootstock brings Bitcoin to Ethereum’s tools, Stacks tries to make Bitcoin itself programmable on its own terms.

Both designs live or die on the peg, and here is the uncomfortable truth that unites them: neither offers what purists call unilateral exit. On a true Bitcoin Layer 2, you can force your funds back to the base chain using Bitcoin’s own consensus even if every operator vanishes or turns hostile. Lightning offers a version of that; the newer statechain and rollup designs are chasing it. Rootstock and Stacks do not have it. Getting your BTC back depends on a federation, in Rootstock’s case, or an elected signer set, in Stacks’s case, behaving honestly and staying online. That does not make them worthless, but it places them in the middle of the trust spectrum rather than at the trustless end, and it is the single most important thing to understand before putting bitcoin on either.

Rootstock: The Merge-Mined EVM Sidechain

Rootstock is the elder statesman of Bitcoin smart contracts. Its mainnet launched on 2 January 2018, which makes it the longest-running EVM sidechain anchored to Bitcoin, per Spark’s analysis. It produces a block roughly every 30 seconds and runs the Rootstock Virtual Machine, which is compatible with the Ethereum Virtual Machine, so contracts written in Solidity and tools built for Ethereum work with little modification. Its native gas asset is rBTC, pegged one-to-one with BTC.

The distinctive part is how Rootstock is secured. It uses merge-mining, which means Bitcoin miners can mine Rootstock blocks at the same time they mine Bitcoin, at no extra energy cost, by including a small commitment in their work. Participation is high: by the second quarter of 2025, merge-mining covered about 87.1% of Bitcoin’s hashrate, equivalent to more than 740 exahashes per second, according to Spark. In practice that means reorganizing Rootstock’s ledger would require marshaling a huge share of Bitcoin’s mining power, a formidable barrier that no separate proof-of-stake validator set can match. Rootstock promotes this openly on its merge-mining page.

The project is developed by RootstockLabs, whose co-founder Diego Gutierrez Zaldivar returned as chief executive in late 2025. A long-standing figure in Latin American Bitcoin circles, he has argued that inheriting Bitcoin’s proof-of-work through merge-mining, rather than standing up a fresh validator set, is what makes Rootstock one of the most secure smart-contract platforms available, and that DeFi on Bitcoin should mean Bitcoin-grade security rather than altcoin speculation, a framing RootstockLabs has repeated across its public updates. That pitch, security by inheritance, is Rootstock’s core identity.

Stacks: Proof-of-Transfer and the Blockstack Legacy

Stacks took a longer, stranger road. It began as Blockstack, founded around 2017 by Muneeb Ali and Ryan Shea with an ambition to build a decentralized internet anchored to Bitcoin. The current Stacks chain launched in 2021, and rather than copy Ethereum it introduced its own smart-contract language, Clarity, which is deliberately decidable, so you can know what a contract will do before running it, and which has no compiler, so the exact source that executes is what gets published on chain. Clarity contracts can read Bitcoin state directly, which lets them react to real Bitcoin transactions.

Stacks does not use proof-of-work or ordinary proof-of-stake. Its consensus is called Proof-of-Transfer, or PoX, and it is unusual in a way that matters for this comparison: miners compete by committing actual BTC, and that committed bitcoin is paid out to STX holders who lock, or stack, their tokens. The October 2024 Nakamoto upgrade cut block times to around five seconds and gave Stacks what it calls 100% Bitcoin finality, meaning that once a Stacks block is anchored, reversing it would require reversing the corresponding Bitcoin block, as explained in a technical review by bex.co. The final piece, sBTC, arrived in December 2024 to provide a two-way peg so that BTC itself, not just STX, can move into Stacks DeFi.

Muneeb Ali has been consistent about the goal for years. Speaking at Consensus in 2023, he argued that Bitcoin needs to become programmable through Layer 2s, that BTC should be usable inside smart contracts, and that the way to unlock it is to put those capabilities in developers’ hands and let them build, as reported by Bitcoin World. Where Rootstock sells security by inheritance, Stacks sells programmability with a Bitcoin settlement guarantee.

The Peg Is the Point: PowPeg vs sBTC Signers

If a Bitcoin sidechain has a single point of concentrated risk, it is the peg: the mechanism that holds the real BTC while a representation circulates elsewhere. Rootstock and Stacks solve it very differently, and comparing the two is the most useful thing a prospective user can do.

Rootstock uses the PowPeg. It is a 5-of-9 multisig federation whose signing keys live inside hardware security modules manufactured by Ledger, so that even the operators cannot extract the private keys, according to Spark. The nine pegnatories are named entities, including Luxor, Sovryn, Xapo Bank, BlockVenture, Constata, pNetwork, Earn, and RootstockLabs, which holds two seats. Moving BTC in requires 100 Bitcoin confirmations (about 16 hours) and a minimum of 0.005 BTC; moving it back out requires roughly 200 confirmations (about 33 hours). The design leans on hardware and on the reputations of known companies.

Stacks uses the sBTC signer set. At launch it moved forward with 14 elected signers out of an intended 15, and it requires a 70% threshold, meaning 10 of 14 signers, to authorize sBTC transactions, as Hiro detailed in its breakdown of SIP-028. The signers are chosen by the community through the SIP governance process, with a stated plan to widen the set and decentralize further over time. Compared with Rootstock’s fixed corporate federation, Stacks is trying to make its peg custodians more numerous and more replaceable, though it is still early in that process.

The honest summary is that both pegs are trusted, not trustless. On Rootstock, five of nine known companies could in principle collude; on Stacks, ten of fourteen elected signers could. Neither lets you claw your bitcoin back to the base chain by yourself if the operators fail. The table below lays the two architectures side by side.

What Merge-Mining Buys, and What It Does Not

Rootstock’s 87% merge-mining figure is genuinely impressive, and it is easy to over-read. What that hashrate protects is the ordering of Rootstock’s blocks: it makes rewriting Rootstock’s transaction history prohibitively expensive, because an attacker would need to out-mine a large fraction of Bitcoin itself. That is a real and rare property; most sidechains and Layer 2s secure their ordering with a small validator set or a single sequencer.

But block ordering is not the same as custody of your coins. The rBTC in your Rootstock wallet is backed one-to-one by BTC held in the PowPeg, and that backing rests on the 5-of-9 federation and its hardware, not on hashrate. No amount of merge-mining stops a peg failure if the federation’s signing process is compromised or its code is flawed. This is the distinction that trips up newcomers: a chain can be extraordinarily expensive to reorganize and still expose you to bridge risk. When you read that Rootstock is secured by most of Bitcoin’s mining power, mentally separate the security of the ledger from the security of the peg. They are two different guarantees, and only one of them is backed by all those exahashes.

Stacks faces the mirror image of the same issue. Its Bitcoin finality makes reversing settled Stacks blocks as hard as reversing Bitcoin blocks, a strong ordering guarantee. Yet sBTC’s backing still depends on the signer set, not on that finality. In both systems, the chain-security story and the peg-security story need to be evaluated separately, and the peg is where the money actually sits.

Proof-of-Transfer and the Case for Real Bitcoin Yield

One of Stacks’s most distinctive features is that it can pay you in bitcoin, not in its own inflationary token. Because PoX miners commit real BTC to compete for the right to produce blocks, and that BTC flows to stackers, the yield that STX holders earn is denominated in bitcoin that came from actual economic activity rather than from printing new units. Over the years since 2021, Stacks has distributed thousands of bitcoin to stackers through this mechanism, a point crypto.news highlighted in its 2026 review of STX.

Stacks has been pushing that idea further. Its Dual Staking pilot, which pairs sBTC with STX, had drawn more than $100 million in participation since launching in late 2025 and advertised yields of up to 10% APY paid in bitcoin, according to the project’s Q1 2026 snapshot. The PoX-5 hard fork, activated in mid-2026, extended the model into what Stacks calls Bitcoin Staking, letting BTC holders earn yield without surrendering custody to a lending desk, as crypto.news noted in the same review. Whether those rates hold as the pilot scales is an open question, but the source of the yield is unusually clean by crypto standards.

Rootstock generates yield the way most DeFi does: through lending, trading fees, and liquidity incentives inside its applications, not through the base protocol paying out bitcoin. That is neither better nor worse in the abstract, but it is a different risk profile. Yield that comes from a protocol paying out fees it actually collected tends to be more durable than yield propped up by token emissions, a distinction that matters more than ever after a year in which several high-TVL Bitcoin yield venues unwound. Readers weighing how to put idle bitcoin to work, whether by staking, lending, or borrowing against it, will find the trade-offs laid out in our guide to borrowing against crypto.

The DeFi Scoreboard

For all their architectural differences, Rootstock and Stacks are competing for the same scarce thing: bitcoin that its owners are willing to put to work on a sidechain. After the 2026 shakeout, that pool shrank hard. Bitcoin DeFi TVL fell about 74% from its roughly $9.1 billion peak in October 2025, and sat near $4.11 billion at the start of September 2026, per Spark research, with most of that concentrated in Babylon’s staking rather than in sidechain DeFi.

On Rootstock, DeFi TVL peaked around $260 million in April 2025 and had fallen to roughly $98 million by early 2026, according to Spark, with two protocols accounting for most of it: Money on Chain, which mints a bitcoin-collateralized stablecoin and held about half of Rootstock TVL at its peak, and Sovryn, a lending and trading protocol that held about a quarter. Concentration is a recurring theme on Rootstock; a small number of applications carry the whole ecosystem.

On Stacks, sBTC climbed quickly after its cap was lifted, peaking around $545 million in the first quarter of 2026 and closing that quarter near $437 million, as reported via Chainwire, before retracing well below those levels as the sector contracted. Capital actively deployed across Stacks DeFi applications sat around $121 million, led by Zest Protocol at $75.9 million (described as the largest bitcoin lending market on any Bitcoin layer), Granite at $26 million, and StackingDAO at $20 million, per the Stacks snapshot. The two ecosystems are strikingly close in size once you separate the peg asset from active DeFi, which is part of why the head-to-head is worth having at all.

A word of caution on all of these figures: they are snapshots, and the most granular breakdowns available are from earlier in 2026. TVL on both chains moves with the bitcoin price and with sentiment, and precise live totals are notoriously hard to pin down. Treat the scoreboard as a picture of scale and structure, not a live ticker.

Sovryn, the Protocol That Runs on Both

The tribal framing of Rootstock versus Stacks obscures how much the ecosystems overlap. The clearest example is Sovryn, which is both one of Rootstock’s nine PowPeg pegnatories and a lending-and-trading protocol that operates across Rootstock and Stacks. Builders in Bitcoin DeFi tend to be pragmatic about which chain they deploy on, and liquidity migrates toward wherever users and incentives are, not toward a single winner declared in advance.

The application mix on both chains is also converging on the same primitives that define DeFi everywhere: overcollateralized lending, stablecoins minted against bitcoin collateral, and decentralized exchanges. Money on Chain and Zest are lending-and-stablecoin plays; Sovryn and Stacks-native venues such as Bitflow run exchanges. Anyone who has used a Uniswap-style automated market maker will recognize the mechanics, and the same questions about liquidity depth, slippage, and impermanent loss apply; our look at AMM design in 2026 covers how those trade-offs shape returns for liquidity providers. The point is that the interesting differences between Rootstock and Stacks live at the protocol layer (security, peg, yield source), not at the application layer, where both are simply rebuilding the familiar DeFi toolkit on Bitcoin.

The SEC Test Stacks Already Took

Here is where Stacks holds a genuinely unusual card. In July 2019, its predecessor Blockstack became the first company to conduct a token sale qualified by the U.S. Securities and Exchange Commission under Regulation A+, the framework normally used for small public offerings. The SEC qualified the offering statement on 10 July 2019, and Blockstack raised about $28 million in cash, alongside roughly $12 million in tokens allocated to an app-incentive program, as Crowdfund Insider reported at the time. The law firm Jones Day, in its analysis of the milestone, noted that it was the first issuance of a digital token qualified under Regulation A+, reached after a roughly ten-month review and around $2 million in legal and compliance work.

That precedent matters for anyone trying to understand where Bitcoin DeFi sits with U.S. regulators. Most token projects have spent the years since either avoiding the SEC or fighting it. Blockstack instead walked in the front door, registered the offering, and later argued that the network had become sufficiently decentralized that ongoing securities-style disclosure was no longer required. Whether or not one agrees with that conclusion, it gave Stacks a paper trail no rival can claim, and it framed STX as a token that engaged the securities question directly rather than pretending it did not exist.

Rootstock’s regulatory profile is quieter and, in one sense, simpler. rBTC is a representation of bitcoin rather than a freshly issued investment token, which raises fewer securities questions, while the RIF utility token sits alongside it. Neither chain is insulated from the broader 2026 fight over how the U.S. will regulate digital assets, a fight now centered on the market-structure legislation working through the Senate, which we track in our coverage of DeFi compliance and the CLARITY Act. But on the narrow question of whether a Bitcoin DeFi token can face the SEC and survive, Stacks answered it years ago.

The Liquid Lesson: When a Federated Peg Breaks

September 2026 delivered a sharp reminder of what is actually at stake in a federated peg. The Liquid Network, a Bitcoin sidechain run by a federation of exchanges and businesses, lost around $320 million when an attacker exploited a bug in its range-proof verification code, minting roughly 4,000 unbacked L-BTC and pegging them out to real bitcoin in about 35 minutes, as crypto.news documented. Critically, no federation keys were stolen. The 11-of-15 multisig signed a peg-out that looked valid because the underlying code accepted a forged proof, a failure mode Chainalysis traced to a cache that returned a stored valid verdict for invalid data.

The relevance to Rootstock and Stacks is direct. Their pegs, a 5-of-9 federation and a 10-of-14 signer set, protect against dishonest operators, but a multisig cannot catch a consensus or verification bug in the software every participant runs. Liquid’s signers were honest; the code was not. A clean audit is no guarantee either, since audits inspect code at a point in time and cannot rule out every latent flaw, a limitation we examine in our piece on the crypto audit badge problem. The lesson is not that federated sidechains are doomed, but that the peg is where risk concentrates, and users should size their exposure accordingly.

This is also why the sector’s technical roadmap keeps circling back to trust-minimized pegs. Ethereum’s Vitalik Buterin warned back in 2022 that there are fundamental limits to the security of bridges that move assets across separate zones of sovereignty, in comments reported by Cointelegraph. Rootstock and Stacks both sit inside that warning. Newer designs using BitVM-style fraud proofs and covenants aim to shrink the trusted set toward a single honest participant, but neither veteran chain has adopted such a peg yet.

Where Each One Fits Now

After all of this, the two are best understood not as rivals for a single crown but as different tools. Rootstock is the conservative choice: a mature, EVM-compatible sidechain with the strongest chain-security story in the category, appealing to Solidity teams and to institutions that want Bitcoin exposure with familiar tooling and known corporate custodians in the peg. Stacks is the more ambitious choice: a programmable Bitcoin chain with a distinctive language, real bitcoin yield through PoX, a decentralizing signer set, and a regulatory track record that no competitor matches.

Both, though, are being squeezed from two directions. Below them on the trust spectrum sits wrapped bitcoin on Ethereum, a custodial IOU that still dwarfs every native Bitcoin DeFi venue by size and remains the path of least resistance for most users. Above them, in terms of trust minimization, sit the newer zero-knowledge rollups such as Citrea and the channel-free payment layers such as Ark and Spark, which are chasing the unilateral exit that neither Rootstock nor Stacks provides. The veterans occupy a defensible but contested middle. Whatever peg you use, custody of your own keys off the sidechain remains the foundation, which is why the hardware you sign with still matters; our review of 2026 hardware signers covers the devices that guard the base-layer BTC these pegs ultimately depend on.

What to Watch Into 2027

Several threads will decide whether either chain regrows or fades. On Stacks, watch how far the sBTC signer set actually decentralizes beyond its initial fifteen seats, and whether Bitcoin Staking under PoX-5 attracts meaningful BTC now that holders can earn yield without handing coins to a custodian. On Rootstock, watch the institutional push and whether its DeFi TVL can climb back toward its 2025 peak or stays stuck under $100 million.

The bigger variable sits at the base layer. Both chains would benefit enormously from a Bitcoin soft fork that enables covenants (proposals such as OP_CTV and OP_CSFS have circulated for years), because covenants are the ingredient that could let a sidechain offer a genuinely trust-minimized peg with something closer to unilateral exit. If that arrives, the distinction between today’s federated veterans and tomorrow’s trust-minimized designs narrows. If it does not, Rootstock and Stacks keep competing on the terms they have now: security by inheritance versus programmability with yield.

The likeliest outcome is not a single winner but a durable split. Rootstock will keep serving developers who want Bitcoin-secured EVM contracts; Stacks will keep serving those who want native yield and programmability with a settlement guarantee. The shakeout thinned the field, and being one of the two oldest survivors is itself a kind of moat. In a sector where most Bitcoin Layer 2s launched in the past two years, Rootstock and Stacks have the one thing that cannot be forked: time.

Frequently Asked Questions

Is Stacks or Rootstock the better Bitcoin Layer 2?

There is no single winner; they suit different needs. Rootstock is better for developers who want Ethereum-compatible smart contracts secured by Bitcoin merge-mining, and for users who prefer known corporate custodians in the peg. Stacks is better for those who want native bitcoin yield through Proof-of-Transfer, faster settlement with Bitcoin finality, and a chain with a regulatory paper trail. Neither offers unilateral exit, so both ask you to trust their peg operators.

Is sBTC safe, and how is it different from wrapped Bitcoin?

sBTC is backed one-to-one by BTC held by an elected signer set that requires a 70% threshold (10 of 14 signers at launch) to move funds, which is more decentralized than a single custodian but is still a trusted group rather than a trustless system. It differs from wrapped bitcoin on Ethereum, which is typically held by one custodial company. sBTC spreads that trust across multiple community-elected signers, with a plan to decentralize further, but it is not immune to peg risk.

Does Rootstock really use Bitcoin’s hashrate?

Yes. Rootstock is merge-mined, so Bitcoin miners can secure it at the same time they mine Bitcoin, and by the second quarter of 2025 about 87% of Bitcoin’s hashrate was participating. That makes reorganizing Rootstock’s blocks extremely expensive. Note, though, that this protects the chain’s transaction ordering, not the rBTC peg, which depends on a 5-of-9 federation rather than on hashrate.

Can you earn real bitcoin yield on Stacks?

Yes, and it is one of Stacks’s most distinctive features. Under Proof-of-Transfer, miners commit real BTC to compete for blocks, and that bitcoin is paid to STX holders who stack their tokens, so the yield is denominated in bitcoin rather than in an inflationary reward token. The Dual Staking pilot advertised yields of up to 10% APY in bitcoin, though rates can change as participation grows.

Is STX a security under SEC rules?

Stacks has the most direct history with that question of any token here. Its predecessor Blockstack ran the first SEC-qualified token offering under Regulation A+ in 2019, then later argued the network had decentralized enough that ongoing securities-style disclosure was no longer required. That does not settle the matter for all time, and the broader U.S. market-structure rules are still being written, but no other Bitcoin DeFi token has engaged the SEC as directly.

Marcus Okafor covers Bitcoin infrastructure and market structure for HOGE Wire.