On this page
Since 1985, choosing 60% stocks and 40% bonds over an all-equity portfolio has changed a household’s trailing 20-year annualized return by as much as 3.1 points a year. That gap opens before a single decision about which strategy to run inside the equity sleeve, which wrapper to hold it in, or which account to put it in. The split itself is the first and largest lever on this site.
Why one ratio moves the number this much
A “20-year annualized return” is what a dollar invested at the start of the window would have compounded to by the end, expressed as a yearly rate. Run that calculation every month since 1985 and each mix traces its own line: more equity means a higher line most of the time, because stocks have carried a higher long-run return than bonds over this sample, and the 40-point gap between 100% and 60% equity is enough exposure to that difference to move the annualized result by a point or more in most decades.
The pattern is not new to this data. In 1986, Brinson, Hood and Beebower found that a pension fund’s policy mix explained, on average, 93.6% of the quarter-to-quarter swings in that fund’s own returns over time, a different measurement from the rolling-window gap here but the same underlying point: the mix a portfolio holds explains most of what happens to it afterward, before a manager does anything else.
The one stretch where the safer mix won
The 20-year window ending March 2009 is the exception worth naming, because it is the only one since 1985 where 60/40 beat 100% equity. That window opened in 1989 and closed inside the first year of the 2008 financial crisis, so it contains both the dot-com crash and a fresh equity collapse without the recovery years that came after either one. An all-equity portfolio carried the full weight of both drawdowns; the 40% bond sleeve carried none of the second one and softened the first. The gap was small, about 0.8 points a year, but the direction flipped.
That one window is what the bond sleeve is for in a mix built to reduce risk rather than maximize return: a long enough sample eventually contains a stretch where the safer asset was not just safer, but better. This card takes no position on where interest rates or credit spreads go from here; it only reports what happened when a stock-heavy period ended inside a crisis.
What this mix decision does not cover
This card is about the split itself, held fixed, not about what happens inside either sleeve. A further tilt inside the equity side, toward cheap stocks or against the cap-weighted index, is a separate decision covered under Equity strategies. Whether to hold that split for the rest of a household’s life, or slide it down as retirement approaches along a glide path, is a third decision this card does not make either. It only answers how much the ratio between stocks and bonds, on its own, has been worth.