Bitcoin L2s are no longer a experiment. Here's what's actually being built.
BTC was digital gold. In 2026, it's becoming a DeFi platform.
For years Bitcoin was one thing: store of value.
That's changing fast.
Here's what's happening on the Bitcoin L2 layer right now:
Rootstock (RSK) now holds over $160 million in TVL. It's an EVM-compatible sidechain that brings Ethereum-style smart contracts to Bitcoin's proof-of-work security model.
Merlin Chain uses ZK-rollup technology to compress Bitcoin transaction data. Cheaper transactions, faster settlement. It's built by Bitmap Tech and has been growing its developer base quietly.
Stacks (STX) has smart contracts that settle directly to Bitcoin. DeFi, DEXs, lending, all anchored to $BTC security.
Lightning Network is handling cheap, fast payments. Not DeFi, but the payment rail that makes micropayments actually viable.
What this means practically:
Bitcoin is moving from "hold and forget" to collateral in DeFi protocols, gas for apps on BTC-anchored chains, and the base layer for an entirely new ecosystem.
The key question isn't whether this works technically. It's whether developers and users will show up at scale, or stay on Ethereum and its rollups.
That answer is being written right now.
I'm watching Rootstock and Merlin Chain specifically. The TVL growth tells you where the capital is paying attention.
What's your view on Bitcoin DeFi?
