Municipal bond exchange traded funds have enjoyed a solid uptrend since the beginning of 2011 despite a brief hiccup due to Meredith Whitney’s doomsday default prediction that didn’t play out.

Now muni ETFs are at multiyear highs with expectations taxes will rise next year providing the asset class with a tailwind after Obama’s re-election. The tax-exempt status of muni bonds would be even more attractive if taxes go up.

However, this week’s appointment of Elisse Walter to head the SEC could force institutional investors to take pause. The new SEC chief has been critical of the muni bond market.

Walter, one of five SEC commissioners, has spent a considerable chunk of her time at the regulator looking at the $3.7 trillion muni market, MarketWatch reports.

Walter has been “a key proponent of municipal-bond reforms such as setting up a uniform, detailed federal-disclosure system for the industry,” according to the report.

On Monday, President Barack Obama nominated Walter to replace Mary Schapiro as the next chair of the SEC.