Another answer contrasts negotiable instruments like currency with the example of a car where a thief of the car doesn’t “own” the car and cannot transfer ownership. What is it about a car that makes it different from the currency?
The question makes more sense if you ask it in the other direction.
Everything that is not currency, pretty much, is like the car.
Currency is the pretty much singular exception to this rule, by sheer force of laws designed to facilitate free transferability of currency without friction. Currency is special property because it is defined as such. See also this answer.
At least from the UK perspective, it's important to recall that the bearers of currency do not own it.
The issuing bank owns banknotes, and the Crown owns coinage (with coinage being a much older form of currency than banknotes).
Because the bearers do not own the currency, title cannot be stolen from them. What instead is stolen, when currency is stolen in the conventional sense, are the rights associated with the possession and which exist between the bearer and the issuer.
When currency passes, ownership of the currency itself does not transfer, but rather the old bearer's rights are extinguished and new rights are created for the new bearer (i.e. it is not an assignment of existing rights).
Therefore, when an innocent person comes into possession of currency, they acquire the new rights bestowed by possession, but they do not have any liability to any previous bearer whose rights were wrongly extinguished - only the wrongdoer has that liability.
This is different from the general principle with ownership of chattels, where title cannot be conveyed unless the seller himself has good title (although there were historically some exceptions like "market overt").
Various kinds of money have always had special treatment in law, and the English common law predates the widespread use of coinage (and in particular, fiat coinage), so it is not always easy to reconcile the various principles.