When the U.S. federal government spends more than it collects in taxes, it borrows the difference by issuing Treasury securities — IOUs sold to investors and held as financial assets. Treasuries are the most widely traded debt instruments in the world and the foundation of the global financial system. Understanding what they are, who buys them, and how they work explains a lot of how government finance and interest rates actually function.
The Basic Idea
A Treasury security is a loan from an investor to the U.S. federal government. The investor pays a price upfront, the government pays interest periodically, and at maturity the government returns the face value (principal). Because Treasuries are backed by the “full faith and credit” of the U.S. government — meaning the federal government’s ability to tax and to issue currency — they’re considered the safest dollar-denominated debt in existence and serve as the benchmark against which other interest rates are priced.
The Four Main Types
- Treasury bills (T-bills) — Short-term debt with maturities of 4, 8, 13, 17, 26, or 52 weeks. Sold at a discount to face value rather than paying coupon interest. If you buy a $10,000 26-week T-bill for $9,800, you collect $10,000 at maturity — the $200 difference is your interest
- Treasury notes (T-notes) — Medium-term debt with maturities of 2, 3, 5, 7, or 10 years. Pay a fixed coupon interest rate every six months and return face value at maturity. The 10-year Treasury note is the most-watched bond in the world and serves as a benchmark for mortgages and corporate borrowing
- Treasury bonds (T-bonds) — Long-term debt with maturities of 20 or 30 years. Pay fixed coupon interest every six months. Used by pension funds, insurance companies, and long-term investors seeking duration
- TIPS (Treasury Inflation-Protected Securities) — Issued in 5, 10, and 30-year maturities. The principal adjusts with the Consumer Price Index, so the inflation-adjusted value is preserved. Pay a real (inflation-adjusted) coupon. Used by investors seeking protection against unexpected inflation
The Treasury Department also issues Floating Rate Notes (FRNs) tied to T-bill rates and U.S. Savings Bonds (Series EE and Series I) sold directly to retail investors through TreasuryDirect.gov.
How Treasuries Are Sold
The Treasury Department issues new Treasuries through scheduled auctions. Primary dealers (large banks designated by the New York Fed) and other institutional investors submit bids; the lowest yield that fills the offering becomes the auction rate. Once issued, Treasuries trade actively in a secondary market where prices fluctuate based on supply, demand, and changing interest rate expectations.
Individual investors can buy Treasuries directly through TreasuryDirect.gov in noncompetitive bids — meaning they accept whatever yield the auction sets — or buy them on the secondary market through brokerages. There’s no commission to buy newly issued Treasuries through TreasuryDirect.
Who Holds U.S. Treasuries
The roughly $35+ trillion in outstanding federal debt is held by a mix of investors:
- Foreign governments and investors — hold roughly $8 trillion combined. Japan and China are the two largest sovereign holders, followed by the UK, Belgium, and other countries. Foreign holdings reflect global demand for safe dollar assets
- The Federal Reserve — holds Treasuries acquired through open market operations and quantitative easing. The Fed’s Treasury holdings peaked around $5.7 trillion in 2022 and have since declined under quantitative tightening
- U.S. mutual funds, pension funds, and insurance companies — hold trillions as part of their fixed-income portfolios
- State and local governments — hold Treasuries in pension reserves and operating accounts
- Individual investors and money market funds — hold short-term T-bills and bonds for safety and income
- Intragovernmental holdings — about $7 trillion held by Social Security and other federal trust funds. These are technically debt the government owes itself
How Treasury Prices and Yields Move
Treasury prices and yields move in opposite directions — this is one of the most consistently confusing parts of bond markets. If you buy a 10-year Treasury paying a 4% coupon, and market rates later rise to 5%, your bond becomes less attractive (because new bonds pay more), so its price falls. Conversely, if rates fall to 3%, your bond becomes more attractive, and its price rises.
This price-yield inverse relationship is why “rising rates” can cause bond portfolios to lose value even though the coupons are still being paid. Longer-maturity bonds have more price sensitivity to rate changes than short-term bills, which is why the 2022 rate hike cycle was much harder on long-duration bond funds than on T-bill funds.
Why Treasuries Matter Beyond the Government
Treasury yields serve as the benchmark for nearly every other interest rate in the U.S. economy. Corporate bond yields are quoted as a spread above the Treasury yield of similar maturity. Mortgage rates closely track the 10-year Treasury. Bank lending rates incorporate Treasury yields as their baseline. Even foreign government and corporate bonds are often priced relative to U.S. Treasuries.
This central role makes the Treasury market the deepest and most liquid securities market in the world — routinely trading over $700 billion per day. The role of Treasuries as a safe haven, reserve asset, and benchmark rate is one of the most important reasons the U.S. dollar remains the world’s dominant reserve currency.
The Bottom Line
Treasury securities are debt issued by the U.S. federal government in four main forms — T-bills (short term), T-notes (medium), T-bonds (long), and TIPS (inflation-protected). They’re considered the safest dollar-denominated investment, serve as the benchmark for nearly every other interest rate, and are held by foreign governments, the Federal Reserve, pension funds, individual investors, and federal trust funds. Prices move opposite to yields, with longer maturities most sensitive to rate changes.