Where the numbers come from
| Series | Source |
|---|---|
| S&P 500 (total return) | A. Damodaran, NYU Stern, histretSP.xls (January 2026 update), sheet "Returns by year" — pages.stern.nyu.edu/~adamodar |
| 10-year US Treasury bond (total return) | A. Damodaran, NYU Stern, histretSP.xls (January 2026 update), sheet "Returns by year" — pages.stern.nyu.edu/~adamodar |
| Baa corporate bonds (total return) | A. Damodaran, NYU Stern, histretSP.xls (January 2026 update), sheet "Returns by year" — pages.stern.nyu.edu/~adamodar |
| 3-month US Treasury bills | A. Damodaran, NYU Stern, histretSP.xls (January 2026 update), sheet "Returns by year" — pages.stern.nyu.edu/~adamodar |
| Gold (US dollar price) | A. Damodaran, NYU Stern, histretSP.xls (January 2026 update), sheet "Returns by year" — pages.stern.nyu.edu/~adamodar |
| US consumer price inflation (CPI-U, December to December) | US Bureau of Labor Statistics CPI-U via FRED (CPIAUCNS, percent change from a year ago, annual), as included in histretSP.xls, sheet "Inflation Rate" |
Calendar-year returns; monthly contributions are spread evenly through each year.
Frequently asked questions
What does a 60/40 portfolio mean?
60% in stocks and 40% in bonds, rebalanced once a year. With $10,000 up front and $500 a month from 1996 to 2025, it grew to $823,041 (8.1% a year); all in stocks would have reached $1.34 million.
Why hold bonds at all if stocks returned more?
For a smoother ride. In 2008 the 60/40 mix returned -13.9%, against -36.6% for stocks alone. A smaller fall is easier to sit through — and easier to live on in retirement.
Does past performance predict future returns?
No. A backtest shows what actually happened with real yearly returns, including the bad stretches, but the future can be better or worse.
Are taxes, fees and inflation included?
Returns are before taxes and fund fees. Inflation is shown separately as the real (after-inflation) return.
Why does the data start in 1972?
The source goes back to 1928, but starting in 1972 keeps the start-year map readable while still covering the 1970s inflation, the dot-com crash, 2008 and 2022.