Should I put my nest egg in a 30-year Treasury bond?

A 30-year Treasury bond is backed by the full faith and credit of the U.S. government, which addresses default risk but not the other risks that come with locking money away for three decades. The most significant is interest-rate risk: when market yields rise, the price of an existing long-dated bond falls, and a 30-year maturity magnifies that sensitivity. An investor who needs to sell before maturity could therefore realize a loss even on a "safe" holding.

Inflation is the other long-horizon concern. A fixed coupon does not adjust, so decades of rising prices can erode the purchasing power of both the interest payments and the principal returned at maturity. That trade-off is why longer maturities typically offer higher yields than shorter ones — the extra compensation is for accepting greater duration and inflation uncertainty, not for added credit risk.

For observers, the key signals are the shape of the yield curve, long-term inflation expectations, and how much of a portfolio a single long-dated position represents. Matching an asset's duration to when the money is actually needed is the central question, and it is one each investor must weigh against their own circumstances.