Hubble is a decentralized lending protocol on Solana that allows users to borrow the stablecoin USDH against their own assets, giving users some liquidity in their long term holdings. Hubble also has a native token HBB which will eventually become the governance token when Hubble becomes a DAO.  Hubble is unique as it charges a one-time 0.5% fee for minting and redeeming USDH, instead of a long-term interest rate. Hubble is best characterized as a Solana-based version of MakerDAO.