This Week in sBTC

Week of June 20, 2023

Dear Bitcoiners,

Bitcoin Summer is finally here! With new ETF rumors swirling, regular breakthroughs on Ordinals, and sBTC development in full swing, it’s off to an exciting start.


✅ Progress on sBTC Alpha testnet. sBTC brings Bitcoin liquidity to the Stacks layer. The protocol makes it easy to create Bitcoin applications that benefit from low fees, improved performance, and full smart contract capabilities. The sBTC working group is making great progress toward the roadmap. The following picture was taken on testnet using the Hiro Wallet.

🔗 Recursive Inscriptions. The latest breakthrough in Ordinals allows inscriptions to request and use data in other inscriptions. This reduces the data stored on-chain and allows for more expressive smart contract functionality. This thread does a great job of ELI5. In short, this unlocks more composeability for ordinals contracts and could enable powerful new use cases for Bitcoin.

🚀 New Hope for Bitcoin ETFs. Last week BlackRock officially filed for a spot Bitcoin ETF. BlackRock will be using Coinbase to custody the ETF. This is a big deal. BlackRock is the world’s largest asset manager and has an ETF approval record of 575-1. Given the SEC has denied every previous Bitcoin ETF application, will this time be different?

Regardless of what happens with the ETF, this summer is for building. With the explosion of new possibilities on Bitcoin, this is the best time to go heads down creating tools and applications. We’ve got you covered with a list of ideas to get started.

Signing Off,


💻 Engineering Updates


  • Successful implementation of sBTC alpha deposits.

  • Withdrawals are still in progress. Support is needed for the sBTC bridge app, including bug fixes #445 #447

  • Requests for other workstreams: introduce support for OP_RETURN withdrawals in the testnet sBTC bridge.

Testing Infra

  • Drafted plan for the sBTC Testing Team to improve and simplify the development process.


  • Reviewing remaining pull requests and updating the roadmap. There’s on-going discussion how to optimize functionality for a minimum-viable product.


  • Updated sBTC roadmap

  • Reviewed WSTS Audit and worked on WSTS Security Proofs


  • Progress on Android UI, incorporating sBTC bridge design scheme.

  • Mock API is nearly complete. Meetings scheduled next week to collect product feedback from key stakeholders.

Better Blocks

  • Organized Better Blocks tasks as a project board.

  • Pull request #3759 is in the review process, and work started on issue #3753.


  • Critical Bounties applications close on Tuesday, June 20th (Today). Don’t forget to submit!

sBTC Bridge:

  • Worked on OP_RETURN withdrawals for sBTC alpha.

  • Implementing the UI/UX design.

⚒️ Go-To-Market Updates

  • Updating the product roadmap to provide clear deliverables for 2023.

  • Completed 15 interviews for the user research study and preparing a report with the takeaways.

🌍 Around the Ecosystem