If you’ve been following the crypto space for any length of time, you know that Bitcoin has always been the king of security and decentralization. But smart contracts? DeFi? That was Ethereum’s territory — until projects like Rootstock (RSK) came along and changed the game. I’ve been diving deep into Rootstock lately, and I think it’s one of the most underrated pieces of Bitcoin infrastructure out there. Let me break down what it is, how it works, and why it’s becoming increasingly relevant in 2025.
What Exactly Is Rootstock?
Rootstock, also known as RSK, is a Bitcoin sidechain that brings smart contract functionality to the Bitcoin network. Think of it as a layer that sits on top of Bitcoin, giving developers the ability to build decentralized applications (dApps) while still leveraging Bitcoin’s unmatched security. It’s actually the first, longest-lasting, and largest Bitcoin Layer 2 in existence — and it’s fully open-source.
The key innovation here is that Rootstock is EVM-compatible. That means if you’re a developer who’s been building on Ethereum using Solidity, Truffle, or Web3.js, you can deploy your smart contracts on Rootstock with minimal changes. You get the programmability of Ethereum combined with the security of Bitcoin. That’s a pretty compelling combo.
Merge Mining: Bitcoin’s Security Without the Trade-offs
One of the most fascinating aspects of Rootstock is its use of merged mining. This is the process where Bitcoin miners can simultaneously mine both the Bitcoin and Rootstock blockchains without any additional computational cost. They’re solving the same cryptographic puzzles for both chains at once.
The result? Rootstock is currently secured by over 60% of Bitcoin’s total hashing power. That makes it arguably the most secure smart contract platform in the world. No other smart contract chain can claim that level of security backing. For institutions and serious builders, this is a massive deal — you’re getting programmability without sacrificing the battle-tested security that Bitcoin is known for.
The Powpeg Bridge: Moving BTC Into DeFi
To use DeFi on Rootstock, you need to bridge your Bitcoin over to the sidechain. This is where the Powpeg comes in — it’s a trust-minimized bridge that converts BTC into RBTC (Rootstock’s native token, pegged 1:1 to Bitcoin). When you lock BTC on the Bitcoin side, the equivalent amount of RBTC is unlocked on Rootstock, and vice versa.
The Powpeg is designed to be as secure as possible, using hardware security modules and a federation of well-known entities to protect the bridge. The Rootstock roadmap has been pushing toward making this even more trustless, with BitVM-based verification on the horizon that could further reduce trust assumptions.
Speed and Scalability
Bitcoin’s base layer processes about 7 transactions per second with 10-minute block times. That’s great for settlement, but not ideal for DeFi interactions. Rootstock addresses this by creating new blocks every 30 seconds on average and processing between 10 and 20 transactions per second. It’s not going to compete with Solana on raw throughput, but for Bitcoin-native DeFi, it’s a significant improvement that makes real applications viable.
Why Rootstock Matters in 2025
The Bitcoin DeFi (BTCFi) narrative has been building momentum throughout 2024 and into 2025. We’re seeing the first major wave of Bitcoin yield strategies emerge — from simple BTC savings with interest to advanced options strategies using BTC as collateral. Rootstock sits at the center of this movement as one of the most mature platforms for building these products.
The ecosystem is growing too. Projects like Sovryn have built full-featured DeFi platforms on Rootstock, offering lending, borrowing, and trading — all secured by Bitcoin. The interoperability story is also compelling: Rootstock enables seamless movement of ERC-20 tokens from Ethereum into Bitcoin-powered smart contracts, bridging two of the largest crypto ecosystems.
Looking at the broader landscape, Bitcoin Layer 2s are having their moment. Lightning Network handles payments, Stacks brings unique smart contract capabilities, and Rootstock provides the EVM-compatible DeFi layer. Each serves a different purpose, but Rootstock’s combination of maturity, security, and developer familiarity gives it a unique edge.
What’s on the Rootstock Roadmap
The Rootstock team isn’t standing still. Their 2024-2025 roadmap includes a Bitcoin native asset bridge for seamless cross-chain transfers of Bitcoin assets like Runes and Taproot Assets into the Rootstock ecosystem. There’s also the RBTC SuperApp in development — an all-in-one dApp that consolidates all available pathways for fast, versatile, and trust-minimized BTC/RBTC transfers.
These developments signal that Rootstock is positioning itself not just as a sidechain, but as a comprehensive Bitcoin DeFi infrastructure layer. With institutional interest in Bitcoin continuing to grow post-ETF, having robust smart contract capabilities on Bitcoin is more important than ever.
My Take
I think Rootstock is one of those projects that doesn’t get enough attention relative to its importance. It’s been quietly building since the early days of Bitcoin Layer 2 development, and now that the market is finally waking up to Bitcoin DeFi, Rootstock is well-positioned to capture a significant share of that activity. The merge-mining security model alone sets it apart from virtually every other smart contract platform.
If you’re a developer looking to build on Bitcoin, or an investor trying to understand where Bitcoin DeFi is headed, Rootstock deserves a serious look. The combination of EVM compatibility, Bitcoin-grade security, and a maturing ecosystem makes it a cornerstone of the BTCFi movement in 2025 and beyond.
Michael Gu
Michael Gu, Creator of Boxmining, stared in the Blockchain space as a Bitcoin miner in 2012. Something he immediately noticed was that accurate information is hard to come by in this space. He started Boxmining in 2017 mainly as a passion project, to educate people on digital assets and share his experiences. Being based in Asia, Michael also found a huge discrepancy between digital asset trends and knowledge gap in the West and China.