With volatility fueling demand for safe-haven assets, municipal bonds and related exchange traded funds are trading around their cheapest relative to Treasuries this year.

For instance, the iShares National AMT-Free Muni Bond ETF (NYSEArca: MUB), which has a 6.32 year duration, shows a 1.61% 30-day SEC yield. The SPDR Nuveen Barclays Municipal Bond ETF (NYSEArca: TFI), which has a 7.34 year duration, shows a 1.91% 30-day SEC yield. The Market Vectors Intermediate Municipal Index ETF (NYSEArca: ITM), which has a 6.98 year duration, shows a 2.13% 30-day SEC yield. [Muni ETFs Could Maintain Strength Going Into 2015]

In comparison, the iShares 7-10 Year Treasury Bond ETF (NYSEArca: IEF), which has a 7.75 year duration, comes with a 1.94% 30-day SEC yield.

Benchmark 10-year munis yield 2.08% while benchmark 10-year Treasuries yield 2.07%. The ratio of the interest rates is a measure of relative value between the two assets, and at about 102%, the ratio is close to its highest in a year, indicating that muni debt have weakened relative to Treasuries, reports Brian Chappatta for Bloomberg.

Safe-haven demand is bolstering the Treasuries market as troubles in Russia fuel volatility concerns and falling oil prices diminish inflation expectations, reports Susanne Walker for Bloomberg.

“It’s causing a flight to quality into Treasuries,” Jason Rogan, managing director of U.S. government trading at Guggenheim Securities, said in the Bloomberg article. “Although attention has moved to the Fed, most eyes are trading off what oil is doing. Russia is leading the charge in the fear.”

The rush to safety has pushed down yields on Treasuries to the point where munis are beginning to look like an attractive alternative fixed-income asset.