Municipal bonds were one of the top performing asset classes in 2015, registering a more than a 3% total return. John Dillon, municipal bond market analyst for Morgan Stanley Wealth Management (MS) , said the solid results should continue this year and spring is the perfect season to start buying. 'There tends to be regularly-occurring periods during the year when it is more favorable to buy or sell municipal bonds,' said Dillon. 'Investors who are aware of these seasonal windows may profit from this.' Dillon said this seasonality was very much on display during the last six months, as compelling value in October and November gave way to an expensive, supply-starved market in December through mid-February, only to turn compelling again by mid-March, which is about where the market is today.