A primer on the basics and complexities of the global bond market. Pima County Government services and news including Tucson, Marana, Ajo, Oro Valley, Sahuarita, Three Points and Arivaca.MUNI MARKET OVERVIEW: Why Do Investors Buy Municipal Bonds? • Generate tax-free income stream. MUNI MARKET OVERVIEW: Why Do Investors Buy Municipal Bonds? • Generate tax-free income stream. Get access to our Dismantling Myths of Investing webinar on demand. "This board is totally out of touch with that reality," Hernandez said. Some current refunding deals were placed to refinance outstanding Build America Bonds in the taxable municipal market. The district's allin debt service coverage (DSC) in fiscal year 2017 grew to 1.9x up from 1.4x in fiscal 2013.