BIV is an intermediate-term bond ETF that adopts a slightly more stringent definition of intermediate by excluding bonds with maturities of under 5 years and over 10. This sets it apart from its competitors and our benchmark, which have broader interpretations of intermediate-term bonds. As such, BIV has a longer average maturity and a slight bias toward lower-rated corporate bonds. Nearly the whole portfolio is in bonds expiring between 5-10 years, compared with about one third for our benchmark. The fund suffers in terms of transparency thanks to Vanguard's monthly disclosure practices.