Solana (SOL) is a powerful cryptocurrency in the portfolio, but diversification is important in the crypto market.Tron (TRX), Kaspa (KAS), and Rexas Finance (RXS) are altcoins that complement Solana and offer unique qualities.Rexas Finance (RXS) enables tokenization of real-world assets, with strong growth potential.Kaspa (KAS) provides scalability through its blockDAG architecture, making it a substitute for investors who value Solana's speed.