Why arrearage matters to investors
Arrearage may or may not be pretty important to you as an investor, depending on what kind of investments you make and what sort of arrearage you're encountering.
If you own real estate investment trusts (REITs), for example, arrearage that is from past-due rents is a serious problem because it represents both tenants who aren't paying and those who may have to be forcefully evicted, which can incur additional substantial costs. If the arrearage is serious and high, it could point to a major problem with your property management team's vetting methods for its tenants. However, some amount of arrearage is normal most of the time.
If your investments are in bonds, you'll encounter arrearage that's perfectly normal and expected. Every bond investor is paid interest in arrears at the maturity of their bonds; this, too, is just par for the course.
For investors in manufacturing, retail, or similar businesses, you may see arrearage in the form of payments the companies are making to their vendors. This is pretty normal behavior and helps your companies do more with their money in the window between the time when the order is placed and when the bill becomes due after delivery.