The certainty equivalent rate of a portfolio is

represented by the scaling factor "−.005" in the utility function.

the rate that a risk-free investment would need to offer with certainty to be considered equally attractive as the risky portfolio.

the rate that equates "A" in the utility function with the average risk aversion coefficient for all risk-averse investors.

the minimum rate guaranteed by institutions such as banks.

the rate that the investor must earn for certain to give up the use of his money.