What is Sei?

Sei is a layer-1 blockchain built on the Cosmos SDK and optimized specifically for trading applications, particularly order-book-based exchanges. It launched with a native on-chain order book at the consensus layer and twin-turbo consensus for faster block finalization, and later added parallelized EVM execution (Sei v2), enabling it to process trading transactions faster than general-purpose Cosmos chains. SEI is the native token used for gas, staking, and governance.

Sei's design philosophy is vertical integration for trading: rather than forcing every DEX to build its own matching engine as a smart contract, Sei launched with a shared order-book module and central limit order book (CLOB) infrastructure that applications could use. This reduces development overhead and enables better capital efficiency across the ecosystem. The chain also implements optimistic block processing — transactions are executed before finality is confirmed, cutting end-to-end latency without sacrificing safety guarantees. Sei v2 expanded the network to support parallelized EVM, making it compatible with Ethereum tooling while retaining Cosmos interoperability via IBC.

Sei faces stiff competition from multiple directions: dYdX v4 built its own Cosmos chain specifically for derivatives and attracted significant institutional order flow; Injective pursues a similar on-chain order-book model with longer market presence; and general-purpose EVM L2s like Arbitrum and Base host high-volume trading apps without trading-specific protocol design. Sei must demonstrate that protocol-level trading infrastructure creates materially better outcomes than application-layer approaches, a case that depends on attracting dominant trading dApps rather than general DeFi usage.

Reviewed by the 2Bitcoins Editorial Team · Updated June 2026. Not financial advice.