For cryptocurrency to be equally interchangeable it must not have a history otherwise there may be individuals that choose not to accept it because they don’t like where it’s been. This has already happened with bitcoin where exchanges have blacklisted certain coins following major wallet thefts. While mixing coins is being attempted by other crypto currencies it is slow and questionable in terms of how private it really is. Stash provides superior fungibility by separating Stash coins from their past transaction history on the blockchain. Stash reveals nothing beyond the fact that somewhere some valid transactions occurred.