In fact, Morningstar categorizes more than 60 municipal bond mutual funds as intermediate, of which several use one of the BarCap Municipal intermediate indices or similar index as a performance benchmark.
It's looked not only at Brent crude but at some other exotic hydrocarbon cocktails - West Texas Intermediate, the Argus Sour Crude Index, Brent Blend or BFOE (the basket of the North Sea's Brent, Forties, Oseberg and Ekofisk), Dubai and Oman, Tapis and Minas, and East Siberia-Pacific Ocean Blend.
Over the years, I have observed consistent weekly patterns in the Relative Strength Index (RSI) that are quite useful in determining both intermediate-term tops and bottoms.