Silvergate ([[SI]] +0.7%) adds Fidelity Investments' digital assets business as a custodian for SEN Leverage, a program that allows institutional investors access to capital through U.S. dollar loans collateralized by bitcoin.The initiative enables institutional investors who currently custody their bitcoin with Fidelity Digital Assets access to SEN Leverage. Investors who want to maintain their long bitcoin positions, for example, can use their bitcoin as collateral without the need to change custody providers or alter their position, Silvergate said.Bitcoin rises 3.9% to $57.9K.Last week, SI said Coinbase Custody will be a custodian for SEN Leverage.