Which of the following hindered development of a secondary market for mortgages in the early $20$th century? Check all that apply.

$$ It was impossible to turn illiquid assets such as real estate into liquid financial instruments.

$$ Institutional investors avoided dealing with financial instruments backed by the federal government, such as mortgages.

$$ Institutional investors could not assess the default risk of every single mortgage.

$$ Institutional investors were not interested in small non$-$standardized financial instruments.