Investors are barreling into municipal bonds, driving yields to record lows and hoping for a safe hiding place at a time when taxes are almost certain to rise.

From Nov. 7 to 12, about $500 million of new money flowed into muni bond funds, according to Lipper U.S. Fund Flows. That compares to $866 million for the entire week ended Nov. 7 and is about the same as the four-week moving average.