Answer:
Risk of a bad investment
Explanation:
When an investor is calculating an investment's interest rate, he/she must include all brokerage commissions and fees
, inflation rate (interest rate must exceed the inflation rate) and the investor's opportunity cost.
Investors are risk adverse, which means that a risky investment should yield a higher return. That could be considered a rational investment rule, but it is not included in the calculation of the interest rate.
