Solana, Polkadot, and Cardano are gearing up for significant protocol upgrades in Q4 2025, aimed at enhancing scalability and governance. These developments are expected to increase on-chain activity and attract more developers. Institutional interest is also on the rise, with Polychain, Galaxy Digital, and Fidelity filing for ETFs. Key figures such as Solana's Anatoly Yakovenko and Polkadot's Gavin Wood have outlined strategic initiatives, while Cardano's Charles Hoskinson has emphasized the importance of the Chang fork. These upgrades are anticipated to boost total value locked (TVL) and draw both retail and institutional investors to these altcoins.