I bought my first tax exempt muni bond CEF about 5 yrs ago, if you got a good entry price close to its historical lows, like MVF that I just bought 2 days ago , the yield is about7.2% tax free. Some tax free muni CEF has had a long years of history. I checked on Yahoo finance /price the history for their inception dates, price behavior/historical low and high, divy yield stability. Morningstar is a very good source to look up other details. In my view it is a quite safe investment, municipals will always need money to fund their existance, and the taxfree design spares me from the headache when filing income tax return. Besides I don't have any luck with stocks, everyone I touched became dirt. But CEF is not as liquid as stocks or ETFs, I wanted to add 500 shares of MYD the other day, only got 140 shares. See the definition of CEF in Investopedia. Do your own due deligent, I only have 5 yrs of experience. Good luck.