To pursue its objective, the Fund normally invests at least 80% of its net assets (including any borrowings for investment purposes) in municipal securities that pay interest free from (a) federal income taxes, including the federal alternative minimum tax, and (b) Oklahoma personal income taxes.

Municipal bonds are debt securities issued by or on behalf of states, territories, and possessions of the United States and their political subdivisions, agencies, authorities, and instrumentalities. The two general classifications of municipal bonds are "general obligation" and "revenue" bonds. General obligation bonds are secured by the issuer's pledge of its faith, credit, and taxing power for the payment of principal and interest. Revenue bonds are payable only from the revenues derived from a particular facility or class of facilities or, in some cases, from the proceeds of a special excise tax or other specific revenue source.

The investment manager actively manages the Fund's portfolio by selecting securities that it believes will provide the best balance between risk and return within the Fund's range of allowable investments. The investment manager will consider selling a security with deteriorating credit or limited upside potential compared to other available bonds.

The Fund may invest up to 30% of its net assets in U.S. territorial obligations (including qualifying obligations of Puerto Rico, the U.S. Virgin Islands, and Guam), the interest on which is exempt from federal and Oklahoma personal income taxes. The Fund may invest up to 20% of its net assets in private activity bonds (which are revenue bonds that finance privately operated facilities), the interest on which is a tax preference item for purposes of the federal alternative minimum tax.

The Fund may invest more than 25% of its net assets in municipal securities that finance similar types of projects, such as education, healthcare, housing, industrial development, transportation, utilities, or pollution control. Economic, business, political, or other changes can affect all securities of a similar type.

All of the municipal securities in which the Fund invests are rated investment grade (BBB- or higher) at the time of purchase by a nationally recognized statistical rating service such as S&P Global Ratings or Moody's Investors Service, Inc. or are of comparable quality as determined by the Fund's investment manager. If, subsequent to the purchase of a municipal security, the rating of a municipal security falls below investment grade, the Fund will not be required to dispose of the security.

Under normal circumstances, the Fund will maintain an average stated maturity at between five and twenty-five years.