A research piece by Castle Labs argues that Bitcoin has reached institutional scale without developing a comparably deep native financial layer. The report says only 311,000 BTC, or about 1.5% of the 20.05 million active supply, is generating any kind of yield, while the other 98.5% remains idle. By contrast, 32.5% of circulating ETH is staked for roughly 2% native yield, with liquid staking products such as Lido’s stETH extending that base layer into broader DeFi. The study maps the current BTC yield stack across three routes: failed centralized lenders, DeFi activity on EVM chains and Solana through wrapped or bridged representations of BTC, and Bitcoin L2 and staking protocols such as Babylon, Lombard, Stacks, Rootstock, and BOB. Each route carries a different trust model. CeFi exposed depositors to opaque counterparties and custody loss, while DeFi requires users to accept bridge, custodian, and smart contract risk. Bitcoin L2 systems move closer to Bitcoin’s trust assumptions, but still rely on signer sets, committees, or staged security models. The report uses Stacks as a case study for what it calls a more Bitcoin-native financial architecture. It highlights Stacks’ Bitcoin-anchored execution, the 15-signer sBTC bridge, and the upcoming PoX-5 upgrade, which is expected in late August and is designed to let BTC holders earn BTC-denominated yield while keeping BTC locked on Bitcoin L1 under self-custody. The paper argues that the core challenge is no longer whether demand exists, but whether BTC finance can grow without pushing holders too far away from Bitcoin’s original security model.

Castle Labs argues that Bitcoin has reached institutional scale without developing a comparable native yield layer. In its review of the BTC on-chain finance market, the firm says only about 311,000 BTC out of roughly 20.05 million active supply — around 1.5% — currently earns any form of yield. The rest, despite Bitcoin’s roughly $1.3 trillion market capitalization and growing role in corporate treasuries, ETFs, and portfolios, remains largely idle. The report breaks the market into three broad routes: failed centralized lending models such as Celsius, BlockFi, and Voyager; BTC deployed into DeFi through wrapped, bridged, or liquid staking-style assets like WBTC, cbBTC, tBTC, and LBTC; and Bitcoin L2 or staking protocols including Babylon, Lombard, Stacks, Rootstock, and BOB. Castle Labs compares the trust assumptions behind each approach, focusing on custody risk, bridge signer risk, smart contract exposure, and slashing. It then uses Stacks as a case study for what it calls a closer-to-Bitcoin model. The paper outlines Stacks’ Bitcoin-anchored finality, the 15-signer sBTC bridge, the proposed PoX-5 upgrade that would let BTC holders earn BTC-denominated yield while keeping coins locked on Bitcoin L1, and an application layer built around Zest, Bitflow, Hermetica, and StackingDAO’s planned stBTC product.

Hashi’s testnet on Sui has drawn participation from more than 25 institutions in a push to let Bitcoin take part in DeFi without leaving the Bitcoin network. The article argues that the market debate has shifted: the question is no longer whether BTC should be programmable, but where that programmability should sit. Hashi keeps the underlying BTC in 2-of-2 multisig Bitcoin addresses while execution happens on Sui, a setup the author says improves asset safety but still leaves users relying on two systems at once. Against that backdrop, TuringBitChain, or TBC, is presented as a different route. Rather than splitting assets and contract logic across chains, it says it writes Turing-complete smart contracts directly into the UTXO model at Layer 1. The piece contrasts the two approaches across trust assumptions, architecture, performance claims, developer trade-offs, and institutional readiness, framing the broader contest around whether programmable BTC finance will be built through external execution layers or within UTXO itself.

The Stacks community has approved SIP-045, the proposal that introduces Bitcoin staking to the network, with more than 99% of votes cast in favor, according to Stacks co-creator Muneeb Ali. The vote clears the way for a hard fork targeted for around July 29 near Bitcoin block 907,740. A companion proposal, SIP-044, also passed, bringing Clarity 6 and new staking post-conditions. Under the new design, participants will be able to lock BTC in a timelocked contract on Bitcoin’s base layer while keeping control of their own keys, then pair that position with locked STX to earn bitcoin-denominated yield. The system uses SPV proofs to verify the Bitcoin-side lock and does not rely on a custodian or a trusted bridge. The paired bonds are designed to target about 3% APY in BTC, while excess rewards are split between STX-only stackers and a reserve pool. The upgrade also restores STX coinbase emissions to 1,000 STX per Bitcoin block from 500, reversing April’s cut. Even so, the vote had little immediate impact on the token price. CoinGecko data cited by The Defiant showed STX trading at $0.144, down 13% over 24 hours, compared with Bitcoin’s 1.9% decline.

Stacks has launched the PoX-5 public testnet, opening the feature to developers ahead of a planned mainnet hard fork. The upgrade is designed to let users stake Bitcoin on the Bitcoin mainnet through time-locking without handing assets to a custodian. Mainnet activation is expected around July 29, with a target Bitcoin block height of 907,740. Stacks also said the initial rollout will include a capacity cap. The move follows community approval of two governance proposals, SIP-044 and SIP-045, which passed with more than 99.99% approval. Stacks said a Bitcoin protocol bond called Genesis Bond is planned as the next step. The update was reported by Techub, citing CryptoBriefing. The announcement centers on pre-launch testing, giving developers a window to try the self-custody staking setup before the hard fork reaches mainnet.

Stacks has published a whitepaper proposing a self-custodial Bitcoin staking mechanism that lets BTC holders earn BTC-denominated yield without bridges, wrappers, or third-party custody. The initial phase targets 3,000 BTC capacity and 3% APY.

Stacks Labs published a technical whitepaper proposing self-custodial Bitcoin staking, allowing BTC holders to earn native BTC yield by locking BTC on L1 and STX on Stacks, without bridging or wrapping. Initial phase targets 3,000 BTC capacity at 3% APY, with full decentralization in phase two.

Stacks has published a whitepaper outlining a self-custodial Bitcoin staking model that lets BTC holders earn native BTC yield without bridges, wrappers, or third-party custody. The initial phase targets 3,000 BTC capacity and 3% APY.