The 30-Year Treasury
A 30-year Treasury is a marketable U.S. Treasury bond that matures 30 years after issuance. Treasury bonds currently come in 20- and 30-year maturities. Their interest rate is fixed at auction, and they pay interest every six months until maturity.
Treasuries are backed by the U.S. government's obligation to pay principal and interest, so they are commonly used as a benchmark for very low U.S.-dollar credit risk. That does not make a 30-year Treasury risk-free for an investor who may sell before maturity. Its market value can move sharply when long-term yields change.
Key Ideas
-
A 30-year Treasury has a fixed coupon determined at auction and pays interest every six months until maturity.
-
Treasury marketable securities can currently be purchased in $100 minimum amounts and $100 increments through TreasuryDirect or eligible banks, brokers, and dealers.
-
Long maturity creates substantial interest-rate sensitivity, but maturity is not duration. Modified duration depends on the bond's coupon, yield, and remaining cash-flow schedule.
-
Holding to maturity removes the uncertainty about the stated principal payment, but it does not remove inflation risk, opportunity cost, reinvestment risk on coupons, or the economic cost of locking in a yield that later becomes unattractive.
Treasury Bond Mechanics
TreasuryDirect describes Treasury bonds as electronic marketable securities with 20- or 30-year terms. The coupon rate is established at auction and remains fixed for the life of that security. Coupon interest is paid every six months.
Investors can:
- buy a new issue or reopening at auction;
- hold the bond until maturity; or
- sell it in the secondary market before maturity.
At maturity, Treasury pays the principal amount. Before maturity, however, the bond's market price changes with prevailing yields and other market conditions.
Price and Yield Move in Opposite Directions
For a conventional fixed-rate bond, a rise in market yields generally makes an existing lower-coupon bond less attractive, so its price falls. A decline in yields generally raises the price of an existing bond with a comparatively attractive coupon.
Long-maturity bonds tend to be especially sensitive because a larger portion of their cash flows arrives far in the future.
Maturity Is Not Duration
A common research error is to treat a 30-year maturity as if the bond had a duration of 30. It does not.
Maturity is the time until the final principal payment.
Modified duration is a first-order measure of price sensitivity to a change in yield. For a relatively small parallel yield change:
Approximate price change (%) ≈ − modified duration × yield change
where the yield change is expressed in percentage points.
For example, if a specific bond has a modified duration of 16 and its yield rises 0.25 percentage point (25 basis points), the first-order estimate is approximately:
−16 × 0.25% = −4.0%
That is an approximation, not a forecast. Convexity becomes more important for larger yield moves, and actual Treasury-curve changes need not be parallel.
Main Risks
Interest-Rate Risk
If long-term yields rise, the market price of an existing 30-year Treasury can decline materially. An investor who must sell before maturity can realize a capital loss even though Treasury continues to make the promised contractual payments.
Inflation Risk
The coupon and principal of a conventional Treasury bond are nominal. Higher-than-expected inflation reduces the purchasing power of those future cash flows. Treasury Inflation-Protected Securities (TIPS) are a different security designed with inflation-adjusted principal mechanics.
Reinvestment Risk
Coupon payments arrive every six months. The rate at which those coupons can be reinvested over three decades is unknown.
Opportunity Cost
Holding a long bond to maturity avoids having to realize a market-price loss, but it can leave the investor locked into an older coupon when newly issued securities offer higher yields.
30-Year Treasury vs. 10-Year Treasury
Both are important long-term benchmark securities, but the 30-year bond generally has greater price sensitivity to long-term yield changes. The 10-year Treasury is a Treasury note, while the 30-year security is a Treasury bond under current Treasury naming conventions.
Comparing their yields can also provide information about the shape of the longer end of the Treasury curve, but the spread between maturities is not by itself a forecast of economic growth, inflation, or equity returns.
How to Buy Treasury Bonds
Treasury marketable securities can be purchased:
- directly through TreasuryDirect with a noncompetitive bid; or
- through a bank, broker, or dealer, which may support competitive or noncompetitive bidding and secondary-market transactions.
TreasuryDirect currently lists a $100 minimum purchase and $100 increments for marketable Treasury securities. Auction pricing and the coupon rate are determined through the auction process; an investor should not assume a particular coupon before results are known.
Research Questions
When analyzing a 30-year Treasury or a fund that owns long Treasuries, ask:
- What is the current yield and coupon?
- What is the bond or fund's modified duration?
- How much would a 25, 50, or 100 basis-point yield move change price under a first-order duration approximation?
- How much convexity matters for the scenario being tested?
- Is the investor likely to hold to maturity or may liquidity needs force an earlier sale?
- How does expected inflation affect the real purchasing power of the cash flows?
- Is the exposure a specific bond, a rolling Treasury fund, or a futures position? Those instruments do not have identical behavior.
Primary Sources
TreasuryDirect — Treasury Bonds
TreasuryDirect — Buying a Treasury Marketable Security
Research Tools
These E7 modules focus on portfolio mechanics, fee drag, rate sensitivity, and policy transmission using deterministic inputs or source-backed explanatory maps rather than hidden live-data assumptions.
30-year Treasury duration stress test
Use an issue's modified duration for a first-order estimate of price sensitivity to a small parallel yield move.
Thirty years is maturity, not duration. Modified duration changes with coupon, yield, and time to maturity. The linear estimate ignores convexity and is most useful for relatively small yield changes.
Continue Research
Continue from the concept into the Grizzly Bulls research surface that best matches the next question. These links are research continuations, not recommendations or required steps.
Explore the Macroeconomic Conditions Index
Add a macroeconomic-conditions lens when interpreting long-duration Treasury exposure.
Explore the Cyclically Adjusted Risk Premium
Connect long-rate research to a separate market risk-premium framework without assuming a deterministic relationship.
Explore more topics in the Financial Research Encyclopedia.