What OP is

Optimism is an Ethereum Layer 2 developed by OP Labs. The OP Mainnet chain is one of the major Ethereum L2s, but Optimism's broader contribution is the OP Stack: an open-source, modular rollup framework that other L2s have adopted, including Kraken's Ink, Worldcoin's World Chain, Sony's Soneium, and others. Together these form the "Superchain": a network of interoperable L2s sharing the OP Stack.

Coinbase's Base, long the largest OP Stack chain, announced in February 2026 that it was moving to its own "unified stack". OP Labs says that stack still shares about 99% of its code with the OP Stack, but Base now runs its own client software, and how it relates to the Superchain and its revenue share going forward has not been publicly settled.

How it works

OP Mainnet is an optimistic rollup that executes EVM-compatible transactions and posts batches to Ethereum L1. OP Stack chains share design but maintain separate state; the Superchain plan involves shared sequencing and atomic cross-chain composability between participating chains. The OP token is governance for the Optimism Collective, the DAO that allocates retroactive public-goods funding to projects building on the OP Stack.

Use cases

OP Mainnet hosts DeFi (Velodrome DEX, Synthetix, Aave), gaming, and consumer apps. The most strategically important piece is the Superchain ecosystem of chains built on the OP Stack. Losing Base, the largest of them, to its own stack in 2026 was a real blow to that story, although the code remains closely shared. The OP token's value derives partly from its governance role over the Optimism treasury and partly from sequencer fees redirected to the Collective.

Tradeoffs and criticism

Like all optimistic rollups, native withdrawals to L1 take 7 days. The Superchain vision creates value but also requires coordination across multiple independent chains, each with their own teams and incentives. OP's tokenomics include a relatively large initial allocation to airdrops and the Collective.

Where to track OP

See optimistic rollup and Layer 2 for technical context.