Overview
Optimism is an Ethereum Layer 2 using optimistic rollups, focused on reducing gas costs and enabling scalable decentralized applications. Launched in December 2021 with the OP token, it pioneered the OP Stack, a modular framework for building interoperable L2 chains. It has positioned itself as a hub for the "Superchain" ecosystem of connected rollups.
How It Works
Optimism processes transactions on its own chain and posts transaction data to Ethereum, assuming batches are valid unless challenged during a dispute window. The OP Stack modularizes the rollup into execution, settlement, and data availability components, allowing teams like Base and other L2s to launch compatible chains. This shared stack makes cross-chain messaging and upgrades easier within its ecosystem.
Why It Matters
Optimism drove the adoption of optimistic rollups and the "Superchain" thesis, where many L2s share infrastructure and liquidity rails. Its retroactive public goods funding model has also influenced how communities allocate treasury resources. Its withdrawal delays and trust assumptions are typical of optimistic systems, and its governance is run through the Optimism Collective DAO.
Related Concepts
Optimism is an Optimistic Rollup using the OP Stack, and it is the home of the Optimism Collective DAO. It connects to Ethereum via Bridges and competes with Arbitrum and Base within the Layer 2 landscape.