XRP, Solana, and Cardano have been the focus of institutional investors in the altcoin market.Bitcoin saw a significant inflow of $284 million, while Ethereum experienced outflows for the fifth consecutive week.XRP attracted $0.1 million worth of inflows, driven by the launch of Grayscale's XRP trust.Institutional investors are expected to fuel a bullish phase in the crypto industry, with potential inflows into altcoins in the coming weeks.