Jack Casey

The regulator was operating with three of five commissioners before Chairwoman Mary Jo White left.

Municipal debt has become more concentrated in the hands of the wealthiest investors, which may prompt lawmakers to rethink the tax-exempt benefits.

An arbitration panel found that a client's complaint about a former wirehouse advisor was "factually impossible or clearly erroneous."

The commission also settled related charges against First Southwest, a financial advisor, for failing to document its advisory relationship with the agency for seven months.

Santander is the latest firm to get hit with regulatory penalties related to the sale of Puerto Rican municipal bonds and close-end funds.