Municipal Bond Market
Municipal Bonds, or Munis, are often tax advantaged, with no Federal taxes, and rarely State taxes if the municipality is in the same state. The total market is about 300,000,000,000 dollars.
I'm thinking that, when the baby boomers retire, the appeal of that tax loophole is going to disappear for them.
I have not found out what percentage of the total Muni market is held by boomers.