Citigroup (C) is shutting down its municipal bonds business, as leadership deemed the unit's economics are "no longer viable." Based on a memo from Head of Markets Andy Morton and Interim Head of Banking Peter Babej, as reported by several outlets, the full closure is expected by the end of the first quarter. Yahoo Finance's David Hollerith analyzes the decision to part ways with the muni bonds group, framing it as part of CEO Jane Fraser's aggressive push to transform operations and boost profitability at the bank. For more expert insight and the latest market action, click here to watch this full episode of Yahoo Finance Live.