This is a move they never played during the Lehman crisis.

This is why - the Muni market is collapsing...

As a reminder, the Muni Bond market had 'broken' with investors desperately using the ETFs to hedge...

Completely decoupling the ETF from the underlying due to lack of liquidity...

Fed Statement:

The Federal Reserve Board on Friday expanded its program of support for the flow of credit to the economy by taking steps to enhance the liquidity and functioning of crucial state and municipal money markets. Through the Money Market Mutual Fund Liquidity Facility, or MMLF, the Federal Reserve Bank of Boston will now be able to make loans available to eligible financial institutions secured by certain high-quality assets purchased from single state and other tax-exempt municipal money market mutual funds.