Investors looking for bargains in the municipal-bond market may find opportunities in closed-end funds that don’t borrow to boost returns.

Unlevered municipal bond closed-end funds traded at a discount to their net asset value of as much 12.6%, according to data compiled by Bloomberg. The biggest, Nuveen LLC’s $1.9 billion Municipal Value Fund, is trading at a 7.2% discount with a tax-exempt yield of 3.97%. Over 20 years, its average discount is 2.3%.