How should we view Starknet's announcement of entering the Bitcoin Layer2 space?

Author: Haotian

In short: 1) Starknet’s expansion into Bitcoin depends on the prior approval of the OP_CAT proposal, which introduces uncertainty; 2) Starknet entering the BTC Layer2 space could help resolve the current imbalance where BTC ecosystems in the East gain traction while those in the West remain underdeveloped; 3) The trend of Layer2s evolving toward Layer1-like independence is strengthening—will high performance become Starknet’s key differentiator? Here’s my take:

1) OP_CAT enables concatenation of multiple UTXO unlocking script byte strings, significantly enhancing programmability on the Bitcoin mainnet. By allowing script fragments to be combined, OP_CAT lays the foundation for leveraging STARK proofs—known for their minimalism and efficiency—for batch transaction processing and ZK validity verification from Starknet to the BTC mainchain.

However, it remains uncertain whether OP_CAT will ultimately be adopted. Even if approved, numerous technical challenges remain in scaling it to handle large volumes of Layer2 transaction batching efficiently. Thus, Starknet's move into BTC Layer2 should currently be viewed more as a narrative than a guaranteed outcome.

Theoretically, once OP_CAT is live, not just Starknet but other Ethereum-based ZK-Rollup Layer2 projects could also enter this space. Other Bitcoin scaling solutions such as BitVM, AVM, RGB, RGB++, and the Lightning Network would similarly benefit. It’s unclear at this stage whether Starknet’s approach would hold a competitive edge.

2) I believe that regardless of whether this is driven by narrative or genuine ambition to expand use cases, Starknet choosing to target BTC Layer2 is a major positive for the overall Bitcoin ecosystem. At minimum, it can attract greater Western capital attention to Bitcoin’s ecosystem and provide stronger validation for the legitimacy of BTC Layer2 initiatives.

Moreover, a project of Starknet’s stature advocating for OP_CAT’s implementation may increase its chances of adoption. Behind such a high-profile push, there may well be strategic capital coordination. (Although Bitcoin Core developer Peter Todd has publicly criticized the move, arguing that Starknet’s involvement adds new reasons to oppose OP_CAT, claiming it could have destabilizing effects on Bitcoin. 🤣)

On the positive side, rallying capital behind Starknet that is bullish on BTC Layer2, integrating developers from Starknet’s ecosystem, and advancing technical standards and innovations tailored for Bitcoin interoperability—all these efforts carry symbolic and catalytic significance. They strengthen Starknet’s overall capabilities and help attract more capital and developers to the BTC Layer2 space.

3) As I’ve previously written, with modular architecture increasingly separating and recombining data availability (DA), execution, and even settlement layers, Layer2 projects are gradually becoming more like Layer1s. Now, even Starknet—one of Ethereum’s most loyal Layer2s—appears to be “defecting.” But this isn’t about growing out of control; it’s about stepping into broader opportunities.

You’ve probably noticed: as both OP-Rollups and ZK-Rollups roll out their Stack strategies, lightweight deployment services like “one-click chain launching” and “Rollup-as-a-Service” have driven the cost and complexity of launching a Layer2 to unprecedented lows. But here’s the problem—what happens when too many chains emerge without corresponding growth in applications and users?

The only answer is to double down on narratives around technical scalability. Starknet recently claimed to already be the highest-TPS blockchain, with fees reduced to $0.01, supporting parallelized transaction processing, and future Volition upgrades promising even lower DA costs. But honestly—Who cares? These metrics alone don’t generate new market expectations.

In contrast, expanding beyond Ethereum into Bitcoin use cases would be transformative for Starknet. Once freed from Ethereum’s shadow, Starknet’s potential would no longer be confined to Layer2 status. Its underlying ZK technology, parallel execution engine, and Cairo language—already built for high performance—would become core differentiators setting it apart from other rollups.

Because for a Layer2 to evolve into something Layer1-like, it must be built on a foundation of ultra-high performance—and Starknet certainly doesn’t lack technical depth. Viewed this way, it’s hard not to see market expectations for Starknet expanding significantly. Who knows—one day Starknet might announce it aims to become a unified ZK layer, or serve as the foundational ZK infrastructure across all blockchains.

Anyway, once it breaks free from the limiting narrative of being “just another Layer2,” Starknet’s potential becomes entirely different.