The MFS Municipal High Yield Muni Bond Fund A (MMHYX) is a mutual fund that primarily invests in high-yield municipal bonds. These bonds are issued by state and local governments to fund various projects and are considered to have a lower risk of default compared to corporate bonds. This fund aims to provide investors with a steady stream of income through the interest payments from these bonds, while also seeking to preserve capital. It is managed by MFS Investment Management, a leading global investment firm, and has a focus on investing in bonds with a shorter maturity period. This fund may be suitable for investors seeking a balance of income and stability in their portfolio.