This fund endeavors to produce significant current income that is exempt from federal taxation, prioritizing the protection of invested capital. To accomplish this, it typically commits a minimum of 80% of its net assets, including any leveraged funds, to municipal bonds that generate income free from U.S. federal income tax. The portfolio primarily comprises municipal and taxable bonds that carry an investment-grade rating (specifically Baa3/BBB- or higher) at the point of acquisition, or, if unrated, are judged to be of equivalent quality by Insight North America LLC, the fund's sub-adviser. The average effective duration of the fund's assets is structured to remain at or below three years. Nevertheless, the fund maintains the flexibility to acquire individual municipal and taxable bonds across all maturities or durations. Duration serves as an indicator of an investment's "interest rate risk," illustrating its susceptibility to changes in interest rates. Generally, a longer duration signifies increased sensitivity to interest rate movements, which can lead to more pronounced long-term risk and return outcomes. Being a liquid exchange-traded fund (ETF), it facilitates investor trading of shares during all market operating hours.