PFMIX is a municipal bond fund offered by PIMCO Funds. It is an institutional class fund, meaning it is designed for larger investors such as institutions and high net worth individuals. The fund primarily invests in municipal bonds, which are debt securities issued by state and local governments to fund public projects. PFMIX aims to provide investors with tax-exempt income while also preserving capital. It may also invest in other fixed-income securities, such as corporate bonds and mortgage-backed securities, to diversify its portfolio. With a focus on municipal bonds, PFMIX may be a suitable option for investors seeking tax-efficient income and potential capital preservation.