$SEI is the native token of the Sei Network, a Layer 1 blockchain focused on high-speed, scalable DeFi and trading applications. It uses delegated proof-of-stake, supports smart contracts, and is used for fees, governance, and staking. Its market cap is ~$2.4B with a fully diluted valuation of ~$5.7B (late 2024). It's seen as a competitor to scalable blockchains like Solana. Cryptocurrency investments are highly volatile and risky; research thoroughly before investing.