Muni funds can also play with the value of your shares to your disadvantage. Muni issues are rarely traded. Muni managers can use any reasonable value for fund assets. Though credit quality may have deteriorated, managers often refrain from writing down asset values for fear of losing shareholders. However, at some point asset values must be marked to market to avoid outright fraud and jail time for the fund managers. If you buy fund shares at a high valuation of assets and later have to redeem when assets are written down to realistic levels, you will justifiably feel betrayed.

Fund managers can also turn tax-free munis into taxable bonds. Capital gains from selling appreciated muni bonds are taxable. Individual savers typically hold munis until maturity so there are no capital gains. Muni fund managers trade bonds. This creates capital gains, often short-term capital gains, which are taxed at the highest rate. Muni funds are outside the comfort zone of most savers.