Eg they also provide 'checking' accounts. There's no conceptual reason why that function needs to be bundled with the 'aggregating default risk' function; but it happens to be so in many countries.
To illustrate, on the one hand, think of an institution that takes deposits and lets you transfer money to pay your rent etc, but doesn't make any 'real' investments: all they do is park the deposits in government loans.
On the other hand, think of exchange traded funds that invest in a wide array of bonds (or even equities). They diversify defaulting risk across the economy, without taking deposits, like your typical bank does.
Eg they also provide 'checking' accounts. There's no conceptual reason why that function needs to be bundled with the 'aggregating default risk' function; but it happens to be so in many countries.
To illustrate, on the one hand, think of an institution that takes deposits and lets you transfer money to pay your rent etc, but doesn't make any 'real' investments: all they do is park the deposits in government loans.
On the other hand, think of exchange traded funds that invest in a wide array of bonds (or even equities). They diversify defaulting risk across the economy, without taking deposits, like your typical bank does.