MainStay MacKay DefinedTerm Municipal Opportunities Fund is an US-based diversified closed-end management investment company. The fund's investment objective is to seek current income exempt from regular U.S. Federal income taxes as well as total return. It focuses on investing in municipal bonds which is of longer-maturity and medium- to lower-quality from certain cities, states, territories or regions. The company may also invest in TOB (Tender Option Bonds) Floaters and TOB Residuals issued by the TOB Issuer. It evaluates its performance against Barclays Municipal Bond Index. The revenue generated by the company mainly consists of interest and dividend received from investments made.