T-Bills (Treasury Bills)

Treasury Bills (T-Bills) are short-term debt obligations issued by the U.S. government with maturities ranging from a few days to one year. They are widely considered the safest risk-free asset class in global finance.

T-Bills do not pay regular coupon interest. Instead, they are sold at a discount to their face value, and when they mature, the government pays the investor the full face value. The difference represents the return. Because they are backed by the full faith and credit of the US government, they carry virtually zero default risk.

In quantitative asset allocation, T-Bills act as the ultimate cash proxy. In Harry Browne's Permanent Portfolio, T-Bills occupy a permanent 25% weight. This cash bucket provides liquidity, absolute capital preservation, and buying power during severe economic recessions or banking panics.

T-Bills also serve as the baseline "risk-free rate" used to calculate the Sharpe Ratio and evaluate absolute momentum filters in tactical strategies. Investors can access T-Bills easily through ETFs like the SPDR Bloomberg 1-3 Month T-Bill ETF (BIL).