Bonds: how they work and why you should care

Bonds are loans. You lend money to a government or a company; they promise to pay you interest on a schedule and return the principal at a specified date. In exchange for giving up ownership upside, you get predictable income and lower volatility. Bonds are less sexy than stocks, less popular than stocks, and mathematically necessary for almost every balanced portfolio.

The main types

• US Treasuries: the safest bonds in the world, effectively zero default risk. Short-term (bills), medium (notes), long-term (bonds) versions.
• Municipal bonds: issued by states and local governments. Interest is usually federal-tax-free, often state-tax-free too for residents. Good for high earners in high-tax states.
• Corporate bonds: issued by companies. Higher yields than Treasuries, with varying default risk by company.
• High-yield (junk) bonds: lowest-rated corporate bonds with the highest yields. Riskier than stocks in some ways; they can correlate strongly with equity drawdowns.
• Inflation-protected bonds (TIPS, I-bonds): principal adjusts with inflation. Not a perfect hedge but useful for preserving real purchasing power.

The key mechanic: rates and prices move inversely

This is the single most confusing thing about bonds. When interest rates go up, existing bond prices go down. When rates go down, existing bond prices go up. This is why 'safe' bond funds can lose 10%+ in rising-rate environments — the bonds they hold are less valuable compared to newly-issued higher-yielding alternatives.

Why hold them at all

Bonds reduce overall portfolio volatility, they provide income during retirement, and historically they've held up or gained value during stock market crashes. The goal of bonds in a portfolio isn't to grow wealth aggressively — it's to reduce the pain of drawdowns so you don't panic-sell your stocks at the bottom. That psychological value is worth real return.

What the numbers on a bond fund page actually mean

Open the page for a total bond market fund like BND or FXNAX and you will see a handful of statistics that tell you nearly everything. The SEC yield — around 4.3% for broad US bond funds in late 2025 — is the best estimate of what you will earn annually at current prices; unlike the 'distribution yield,' it accounts for bonds trading above or below face value. The average duration — about 6 years for a total bond fund — tells you the interest rate sensitivity: rates rising one percentage point should knock roughly 6% off the price, and rates falling one point should add roughly 6%. Credit quality tells you default risk: a fund that is mostly US government and AAA paper can fall in price but is extremely unlikely to suffer meaningful defaults. Those three numbers — yield, duration, credit — replace a thousand pages of prospectus for practical purposes.

2022: the year that rewrote bond expectations

For decades, 'bonds are the safe part' went untested by rising rates. Then 2022 arrived: the Federal Reserve hiked rates from near zero to over 4% in a single year, and the total US bond market fell about 13% — its worst year in modern history — while long-term Treasuries lost nearly 30%. Investors who believed bonds could not have a bad year were blindsided. The mechanics were working exactly as designed, though: prices fell because yields rose, and those higher yields immediately began repairing the damage. An investor who held a total bond fund through 2022 collected 4 to 5% yields in the years after, versus the 1 to 2% available before. The lesson is not that bonds are unsafe; it is that a bond fund's short-term price is volatile while its long-term return converges toward its yield. Match the fund's duration to your holding period and 2022-style losses become recoverable detours rather than disasters.

How much of your portfolio belongs in bonds

Bonds earn their keep in three situations: you are within 10 to 15 years of spending the money, you have discovered you cannot stomach full stock market volatility, or you want dry powder for rebalancing into crashes. A 30-year-old retirement saver can defensibly hold zero to 10% bonds; a 50-year-old might hold 25 to 35%; a retiree drawing income commonly lands at 40 to 60%. Whatever the level, prefer broad, cheap funds — a total bond market index at 0.03 to 0.05% — and resist the urge to reach for exotic higher-yielding bonds, which tend to fail exactly when you need bonds to hold the line. The purpose of this asset class is not to make you rich; it is to make sure the stock side never forces you to sell at the bottom.

A closing rule of thumb ties it together: own bond funds whose duration is no longer than the time until you will spend the money, keep the credit quality high, keep the expense ratio near zero, and judge the holding by the income it pays rather than the price it prints. Bonds held that way do their one job — showing up with stability and spendable yield precisely when stocks are having their worst moments.