The $3.6 billion Nuveen AMT-Free Quality Municipal Income Fund (NEA - Get Report) is the largest tax-exempt closed-end fund (CEF) in the world. Jim Robinson, portfolio manager for the Robinson Tax-Advantaged Income Fund, suggests investors make it even bigger. "It has a trailing 5-year annualized NAV return of 6.54% versus 4.63% return for municipal bond indices. Plus, its current discount is 4% wider than the average fund in the universe," said Robinson. Robinson is also bullish on John Hancock Investors Trust (JHI - Get Report) , which has historically traded at an average premium of 1.6% the past 5 years, but is now trading at a 7.6% discount. Robinson is positive on the Blackstone/GSO Strategic Credit Fund (BGB - Get Report) , which sports a 12% discount, one of the widest discounts in senior bank loan funds. Finally, Robinson is a fan of the Western Asset High Income Fund II (HIX - Get Report) which has traded at an average premium of 1% over the past 5 years and now trades at a 6.6% discount.