iShares 20+ Year Treasury Bond ETF (TLT)

What the fund owns and how it works

TLT seeks to track the ICE U.S. Treasury 20+ Year Bond Index. The benchmark covers U.S. Treasury securities with more than twenty years remaining to maturity, subject to its eligibility rules. The fund receives fixed coupon payments from its holdings, replaces securities as the index rebalances, and distributes income according to fund policy. It does not mature on one shared date like an individual bond.

The portfolio combines U.S. government credit exposure with long interest-rate exposure. Those are separate dimensions. Treasury backing addresses promised payments on the underlying securities, while market yields determine the present value of their distant coupons and principal. A change in required yield can therefore move the fund's market value substantially without any change in the government's payment status.

Why readers compare or use it

TLT is often examined as a concentrated way to observe long-term Treasury rates. Longer cash flows generally carry more duration than short or intermediate Treasury portfolios. That can make the fund respond strongly to changes in expected inflation, economic growth, monetary policy, and the term premium demanded for holding long bonds.

Readers may compare it with AGG, SGOV, or TIP, but each comparison changes more than maturity. AGG adds corporate and mortgage sectors, SGOV stays at the shortest bill maturities, and TIP links principal to inflation. TLT's distinguishing feature is fixed-rate nominal Treasury exposure beyond twenty years.

Trade-offs to understand

Duration provides a useful sensitivity estimate. If a portfolio had a duration of fifteen years, a parallel one-percentage-point yield increase would imply roughly a fifteen-percent price decline before accounting for convexity and other effects. That example is arithmetic, not TLT's current duration or a forecast. TLT's current duration is published by the issuer with its own as-of date.

Yield curves rarely move in perfectly parallel shifts, and bond-price curvature makes the approximation less precise for large changes. Income can partly offset price movement over time, but it does not prevent interim losses. ETF shares also face spread, premium or discount, expenses, and market-liquidity conditions.

Closest alternatives

Intermediate Treasury ETFs reduce maturity and duration while retaining Treasury credit exposure. SGOV operates at the opposite end of the curve with Treasury bills. TIP adds inflation-linked principal mechanics, and AGG combines government bonds with mortgages and investment-grade corporate debt. A single long Treasury bond offers a known maturity, while TLT maintains a rolling long-maturity portfolio.

What can change

Long-term yields, curve shape, duration, yield, distribution amounts, and holding weights change. Treasury issuance and index rebalancing alter the available portfolio. ICE can revise index rules, and BlackRock can update fees or portfolio practices through disclosures. Current interest-rate sensitivity is a dated measure rather than a fixed property. A benchmark or maturity-band change would alter the range of bonds the fund holds.

Evidence and links

Primary evidence: the official iShares TLT page, current fact sheet and prospectus, ICE U.S. Treasury 20+ Year Bond Index materials, and U.S. Treasury security guidance.

Editorial sources

• Benchmark source
• Supporting source
• SEC ETF glossary
• Fund documents
• Fund documents
• Issuer page

Related reading

• AGG
• BND
• HYG
• LQD
• SCHD
• SGOV
• TIP
• USFR
• VIG
• VTV
• Expense ratio
• Inflation
• Liquidity
• Net asset value NAV
• Dividend
• How treasury bills work
• Market index
• What is a bond
• What is an ETF
• What is an index fund
• Yield