Ethereum surged 46% in May, posting its first positive monthly return in 2025, driven by whale and ETF buying pressure.Institutional investors poured $494 million into Ethereum ETFs, signaling a bullish outlook on the altcoin.Analysts suggest Ethereum's breakout versus Bitcoin may initiate a massive altcoin market rally.ETH/BTC forming bullish cup-and-handle patterns, projecting a 30-55% increase for Ethereum against Bitcoin.Bitcoin Pepe raised $13.6 million in its presale, aligning perfectly with the altcoin rotation trend.Solana, testing critical support at $159, shows buy signals and potential for future growth.Bitcoin Pepe aims to bring meme coin trading to Bitcoin's ecosystem, securing partnerships and gaining investor interest.Ethereum, as an infrastructure layer for DeFi and NFTs, is supported by institutional backing for the altcoin season.Solana, with its speed and low fees, positions itself well for meme coin trading and DeFi growth in the altcoin surge.Bitcoin Pepe and Ethereum are highlighted as strong assets for potential gains during the altcoin season.