Today’s Chart of the Day from the Financial Times shows the growth of Bond ETFs from 2007 to present. It shows they are becoming an increasingly popular option. This is due to their lower costs, increased liquidity, transparency of what's inside them, index-like returns, and reduced risk due to higher diversification.
Side note: For years, investors were unsure of how bond ETFs would perform during volatile times. The article goes on to show that they surpassed everyone’s expectations during these times and, in fact, grew even faster. This was primarily due to their increased liquidity and transparency, which during market turmoil is a valuable benefit.