Why T-Bills Are Used When Determining Risk-Free Rates

Why T-Bills Are Used When Determining Risk-Free Rates

3 Min.


In finance, the risk-free rate characterizes the return on an investment without any risk of financial loss. Typically, the prevailing rate of either the current Treasury bill (T-bill) or the yield on long-term government bonds serves as the benchmark for the risk-free rate. T-bills stand out for their minimal default risk due to the comprehensive backing by the U.S. government.

Conversely, the market risk premium denotes the variance between the anticipated return on a portfolio and the risk-free rate. As an integral facet of the Capital Asset Pricing Model (CAPM), it elucidates the intricate interplay between risk and return. Beyond this, the risk-free rate is pivotal in bond pricing, where bond values are frequently delineated as the disparity between the bond's and risk-free rates.

Treasury Bills: Unraveling the Virtually Risk-Free Investment

The concept of a risk-free rate may seem elusive in the world of investments, where risks are inherent. However, due to distinct factors, Treasury bills emerge as an exceptional candidate for achieving near-risk-free status. The U.S. government's impeccable track record of honoring debt obligations, even during severe economic turmoil, underscores the reliability of T-bills.

Functioning as short-term securities with maturities of one year or less, T-bills are typically issued in $1,000 denominations. Auctioned at or below par value, investors receive the full par value upon maturity. This assurance stems from the government's commitment to repay bondholders at par, solidifying T-bills as risk-free assets.

Further enhancing their appeal, T-bills, akin to zero-coupon bonds, mitigate interest rate risk due to their brief maturities and the absence of regular interest payments. Accessible through weekly Treasury auctions, T-bills provide a straightforward investment avenue. Not only are they uncomplicated for investors to comprehend, but they also serve as a means for the government to address the national debt. In specific analyses, yields on long-term government bonds may substitute as the risk-free rate, depending on the nature of the investment under scrutiny.


The risk-free rate in finance, often based on Treasury bills or long-term government bond yields, represents an investment's return without financial loss risk. Treasury bills, with minimal default risk and government backing, exemplify a near-risk-free investment. The market risk premium, a vital component of the Capital Asset Pricing Model, underscores the relationship between portfolio return and the risk-free rate. T-bills, functioning as short-term, zero-coupon assets, offer simplicity for investors and contribute to addressing the national debt. In specific analyses, long-term government bond yields may substitute as the risk-free rate, depending on the investment context.

Treasury Bill
Risk-Free Asset