Dollars in bank accounts are what may be called ‘configurational’ entities: they are states or configurations of objects, not what we usually think of as physical objects in their own right. Your bank balance resides in the state of a certain information-storage device. In a sense you own that state (it is illegal for anyone to alter it without your consent), but you do not own the device itself or any part of it. So in that sense a dollar is an abstraction.
