>The cost savings comes from the fact that instead of having to hire independent auditors to verify the paper trail, the blockchain serves as an immutable audit log and can be verified programmatically.

I don't know enough about the financial industry to know if a real actual problem is being solved here. I do assume that any bank in this industry is already required by law to keep a record of all transactions, and that it's all digitally processed and stored. You'd have to hire an auditor to verify the blockchain software too, and even on the ongoing basis, to audit the infrastructure to make sure it hasn't been improperly modified.