EMMA's updated home page and navigation should help regular folks (the majority of muni bondholders) to make more informed decisions. Some muni bonds are notoriously illiquid - meaning they don't trade that often - but they are a key source of income for a lot of retail investors.
Take Puerto Rico, for example. Since around 70 percent of all muni bond mutual funds hold Puerto Rican municipal debt, everyone has been paying close attention to Puerto Rico's commonwealth muni bonds, which were downgraded recently. This website should be a great way to research these bonds.
The new home page contains a list of most actively traded munis, including one Puerto Rico issue maturing in July 2020 at a price of about 96 cents on the dollar (just under par value, the face value of the bond) and yielding 6.19 percent.
You can also look for high-yielding munis under the heading Advanced Search ( http://emma.msrb.org/Search/Search.aspx). I can, for example, view all municipal issues out of my home state of Delaware maturing in 20 years, or yielding between 7 percent and 8 percent.
Beware: The database is only as good as what issuers submit. One city's data were so bad that the Securities and Exchange Commission cited it for failure to maintain current annual financials on the EMMA website. SEC officials termed the information misleading.
Still, this is a long overdue upgrade to an obscure market. Take advantage of it to understand what is happening in your muni bond portfolio. A tour of the upgrades is available at MSRB's website ( http://msrb.org/msrb1/EMMA/pdfs/EMMA-Homepage-2014.pdf ).