A bond benchmark is a standard reference used to compare a bond's yield, price, or performance against a relevant baseline. For individual bonds, the benchmark is typically an on-the-run Treasury bond with similar maturity — for example, pricing a 10-year corporate bond as 'Treasury +150bp' uses the 10Y UST as the benchmark. For portfolios, bond benchmarks are usually total-return indices (Bloomberg Aggregate, corporate indices, etc.) that capture coupon income, price changes, and reinvestment. Some systems use Treasury yield indices (like ^TNX) as simplified rate proxies, but these are yield-only and miss coupons, roll-down, and credit effects — suitable only for directional rate sensitivity, not total return tracking.