Coinbase announced an expansion of its custody business to allow institutional clients tap into rewards offered by certain types of digital assets running on proof-of-stake networks via “staking” services (a.k.a., "staking as a service"). Starting with Tezos ($XTZ), Coinbase Custody will take about 20 percent from the current 8 percent yield, which means that clients will be able to earn around a little over 6 percent annually.