CGSM aims to generate current income that is exempt from federal income tax while also preserving capital by holding a portfolio of US municipal bonds. Up to 20% of the fund's assets may be subject to the federal alternative minimum tax. The fund is predominantly investment grade paper, holding at least 90% in debts rated BBB- or Baa3 or higher, but it may also invest in junk bonds. Although investments can be of any maturity, the fund will attempt to maintain a weighted average effective portfolio duration of one year. CGSM is managed by a team of portfolio managers who aim to select attractively priced securities believed to be promising investment opportunities. The fund managers may actively and frequently trade, potentially resulting in a high portfolio turnover rate. Additionally, positions are sold if they are no longer considered attractive.