There are many more Bond ETFs than you might realize (250+), making it one of the largest ETF segments. Bond ETFs can be categorized by duration and by type. In terms of duration you have All-Term (a fund with a mixture of durations), and then separate categories of Long-Term, Intermediate, Short and Ultra-Short-term durations.

The most popular bond ETFs are:

(BND) Total Bond Market ETF
(AGG) Core Total U.S. Bond Market ETF
(LQD) iShares iBoxx Investment Grade Corporate Bond ETF.

The bond funds with the highest yields are the ‘junk” bond ETFs, which is the term used to describe bonds from non-investment-grade companies. Examples include:

(HYG) iShares High Yield Corporate Bond Fund
(JNK) SPDR High Yield ETF
(SJNK) SPDR Barclays Capital Short Term High Yield ETF
(EMB) iShares J.P. Morgan USD Emerging Markets Bond ETF .
HYG is the most popular of the high-yield funds.

Yields may be relatively high for these funds compared to Treasuries, but remember that the fund itself has a value that will fluctuate in a much wider range than the yield. In a bond bull market yields are falling and bond prices are rising. In a bond bear market, yields are rising, but bond prices (and the ETFs that track them) are falling. This is why when it comes to bonds, “total return” matters.