(Photo by Kevin Dietsch/Getty Images)Getty ImagesWith the Federal Reserve widely expected to cut rates by 0.25% at its September 16 meeting, attention is turning to where investors can find value in fixed income. Many default to the iShares Core U.S. Aggregate Bond ETF (AGG), which tracks the Bloomberg U.S. Aggregate Bond Index. But just as the S&P 500 captures only part of the equity universe, AGG represents a narrow slice of the bond market, often leaving higher-yielding and diversifying opportunities on ...