Historically, defaults are very rare for investment grade bonds, with default rate for even BBB-rated (the lowest investment grade rating) securities being only 0.15%, on a 1-year time horizon (Figure 7).

Source: https://seekingalpha.com/article/4630752-qlta-etf-when-quality-detrimentail-total-returns-hold?source=feed_all_articles

The narrow slices include ETFs such as IBTG, which only holds US Treasury bonds maturing in 2026, or LQDB, which purely contains BBB-rated corporate bonds.

Source: https://www.ft.com/content/231524e2-fe76-412c-ac84-dbfc365879af

This is also supported by a strong BBB-rated balance sheet with a net debt to EBITDA of 4.1x, sitting below the 4.5x level generally considered to be safe by ratings agencies.

Source: https://seekingalpha.com/article/4607894-kinder-morgan-forget-tech-rally-buy-high-income-bargain?source=feed_all_articles