> how banks are apparently actually using the blockchain for currency trading: There isn’t a single blockchain that we can call “the blockchain” Technically,

> how banks are apparently actually using the blockchain for currency trading: There isn’t a single blockchain that we can call “the blockchain” Technically, a private append-only log is a blockchain if it includes some hashing in each entry to verify the previous entry. This creates a chain of blocks that can be verified to have occurred in a certain order without tampering, though it wouldn’t have the features of a distributed blockchain like cryptocurrencies. This is actually fine for a lot of applications. It’s especially fine if you get a vague business direction to “use blockchain somewhere” and you need to check that box for PR/marketing/investor-pleasing purposes.