Let me see if I understand this: Suppose you had a single broker that held all of its customers' shares in-house (i.e. street name) and that broker represented

Let me see if I understand this: Suppose you had a single broker that held all of its customers' shares in-house (i.e. street name) and that broker represented all the owners of one particular stock. Then it could do low price, high speed settlement because it always knows where all the shares are and moving them around just requires changing a line in a database. The idea with blockchain settlement is to simulate this in a distributed fashion by having a public auditable record of where all the shares of a security are at any moment in time. --- I don't see that either scenario would solve all delivery problems, for example it would do nothing to prevent claw backs if a legal regime demanded it, but I could see how it could speed things up and prevent some game playing.