"Broad money is made up of bank deposits — which are essentially IOUs from commercial banks to households and companies — and currency — mostly IOUs from the central bank.(4)(5) Of the two types of broad money, bank deposits make up the vast majority — 97% of the amount currently in circulation.(6) And in the modern economy, those bank deposits are mostly created by commercial banks themselves."
The information you yourself linked says that 97% of broad money is made up of bank deposits, and that bank deposits are 'essentially IOUs from commercial banks to households'. This supports what I said: that bank deposits are loans from depositors to banks.
A bank can create an unlimited amount of money by issuing a loan: through a simple journal entry, it can create:
- a loan for $1 billion (owed by customer X)
- a deposit account for customer X (containing $1 billion)
But an SPDI can't do that, as it has to have liquid cash for the total amount among all deposit accounts.