$ETH

**Ethereum ($ETH)** is the second-largest cryptocurrency by market cap, known for its smart contract functionality. As the backbone of decentralized applications (dApps), DeFi, and NFTs, Ethereum enables programmable transactions without intermediaries. Its 2022 transition to Proof-of-Stake (PoS) via "The Merge" reduced energy use by ~99.95%. Upcoming upgrades like Dencun aim to improve scalability with proto-danksharding. Despite competition from Solana and Layer 2s, ETH remains dominant due to its security, developer community, and institutional adoption (e.g., ETH futures ETFs). Potential spot ETF approvals could further boost demand. Key challenges include gas fees and scaling, but Ethereum’s roadmap solidifies its Web3 leadership.