An Arkansas-chartered bank or savings and loan association that holds as trustee funds awaiting investment or distribution, if not prohibited by the instrument or judgment creating the trust, may deposit the funds in the commercial department of the bank or savings and loan association. However, if the amount of the deposit exceeds the Federal Deposit Insurance Corporation insurance coverage, the bank or savings and loan association shall pledge, as security for the payment of the deposit, bonds constituting general obligations of the United States or the State of Arkansas of a market value not less than the uninsured portion of the deposit.