Municipal bonds are on pace for a record year

What it means: The buying spree has been prompted by the Fed's rate cutting cycle, which has reduced the attractiveness of other bonds that don't carry munis' tax-friendly status, and the Tax Cuts and Jobs Act, Lipper senior research analyst Pat Keon points out in a recent post.

• The tax law change capped state and local tax deductions at $10,000.

Why you'll hear about this again: "Even with muni yields near multiyear lows, after-tax yields have continued to exceed those of taxable bonds for anyone whose marginal tax rate is 24% or higher — well below the top tax rate of 37%," Marinella says.

Go deeper: Municipal bonds are 2019's hottest asset