Ethereum, Solana, Sui, and Tron have emerged as leading altcoins in 2025, reflecting shifting market sentiment as indicated by the fear and greed index. Ethereum has seen significant institutional interest, with its ETF assets under management reaching $17 billion by December 26. Solana experienced a surge driven by meme coin and DeFi activity, achieving a new high earlier in the year. Sui has gained traction in both DeFi and institutional sectors through October. Meanwhile, Tron maintained a steady performance with a 9% gain over the past 12 months, bolstered by its stablecoin strategy.