It is lawful for any public entity, as defined in section 24-75-601 (1), C.R.S., to purchase anticipation warrants issued in pursuance of section 23-20-125 if such warrants satisfy the investment requirements established in part 6 of article 75 of title 24, C.R.S.; but not to exceed twenty percent of the total of any specific fund of such public entity shall be invested in such warrants.