ValuationUpdated monthly · data through September 2026

S&P 500 vs Its Long-Term Trend: How Far Above the Line Is the Market?

The growth of a dollar in US stocks since 1881, after inflation and with dividends reinvested, against the straight line that compounding at a constant rate would draw. The gap shows how far prices have run ahead of, or fallen behind, the market's own long-run path, with no earnings involved.

Today's reading

As of September 2026, the S&P 500’s real total return stands +56.2% against its 145-year trend line, which grows 6.6% a year after inflation. Against the trend fitted from 1926 it is +39.6%. Since 1911, months this far above a trend known at the time were followed by a median real return of 1.9% a year over the next decade, against 7.5% for all months, from 6 non-overlapping decades.

Sources, methodology & freshnessLast updated 2026-09 · Open ↓

Source

Robert Shiller, monthly S&P composite price, dividends and CPI, 1881+

Methodology

Real total-return index; log-linear trend; % gap from the line; point-in-time refit for the forward study

Updates

Monthly, when Shiller publishesLast: 2026-09

Maintained & reviewed by Yuriy Matso — methodology shown on the page.

Real S&P 500 vs trend2026-09

+56%

Well above trend

Real total return against its 145-year trend line. ±30% marks the edges of the normal range.

vs 1926 trend

+40%

Trend growth

6.6%/yr

Next 10 yrs, median

1.9%/yr

A dollar in US stocks since 1881, after inflation

On a log scale, growth at a constant rate is a straight line. The dashed line is the best fit through the whole record, 6.61% a year after inflation. The index starts at 10 in January 1881.

The real S&P 500 total return is +56% above its 145-year trend line

Real S&P 500 total returnTrend, 6.6% a year

Monthly, January 1881 to September 2026, log scale. Price change plus reinvested dividends, divided by the consumer price index. Source: Robert Shiller.

How far above or below the line

The gap as a percentage of the trend. The shaded band is ±30%, where the market has spent most of its history. The dashed line measures the same gap against the trend fitted from 1926, the start the widely shared version of this chart uses: today it reads +39.6% there against +56.2% on the full record.

+56% against the 145-year trend; +40% against the trend since 1926

Gap from the 1881 trendGap from the 1926 trend

Percentage by which the real total-return index sits above (+) or below (−) each trend line, monthly. Both lines use the whole record after their start, so each past reading already knows the future slope; section 04 removes that.

Trend from 1881

6.61% real growth a year · today +56.2%

Trend from 1926

6.87% real growth a year · today +39.6%

What real returns followed each zone?

The median real return a year over the following five and ten years, grouped by where the market stood against a trend drawn only from the data known at the time. The months overlap heavily, so the independent count is the number of non-overlapping periods, and it is small.

Starting point	Next 5 yrs, median a year	Next 10 yrs, median a year	10 yrs positive	Independent decades
Above +30% (today)	+2.4%	+1.9%	65%	6
Within ±30%	+9.1%	+8.7%	96%	10
Below −30%	+11.2%	+12.2%	100%	5
All months	+7.7%	+7.5%	87%

Real total return, annualized. Start months from the first month with thirty years of history behind the trend. The widely shared version of this chart instead reports the return earned while inside each zone: above +30% +4.0% a year (24% of months), within ±30% +6.6% a year (58% of months), below −30% +10.5% a year (18% of months) on the full-record trend.

The same gap without hindsight

Here the trend is refit every month on only the data an investor had then, so no past reading borrows from the future. It is the line the study above is graded on. The largest readings of each run above +30%: September 1929 +150%, February 1937 +68%, April 1956 +121%, July 1999 +119%. Today it reads +56%.

Without hindsight, today reads +56%; the 1929 and 1999 peaks read +150% and +119%

From January 1911, when thirty years of data first exist. Early readings swing more because the trend is fitted to fewer years.

Shiller publishes dividends a few months after prices; the latest 3 months carry the last known dividend yield forward. Data: Robert Shiller, shillerdata.com. Download the series: market_trend.json.

Real S&P 500 vs trend2026-09

+56%

Well above trend

Real total return against its 145-year trend line. ±30% marks the edges of the normal range.

vs 1926 trend

+40%

Trend growth

6.6%/yr

Next 10 yrs, median

1.9%/yr

How S&P 500 vs Its Long-Term Trend Works

1
Build a real total-return index
Starting from Robert Shiller’s monthly S&P composite, each month’s return is the price change plus one twelfth of the annual dividend, and the result is divided by the consumer price index. That gives the growth of a dollar invested in US stocks with dividends reinvested, after inflation, since 1881.
2
Fit the long-run trend
On a log scale steady compounding is a straight line, so the trend is the least-squares line through the log of that index. Its slope is the average real growth rate of the whole record.
3
Measure the gap
The reading is the percentage by which today’s index sits above or below the line. Readings above +30% mark the market running well ahead of its own history; readings below −30% mark it well behind.
4
Check it without hindsight
A line fitted to the whole record uses data from the future at every past point. The page also refits the trend each month on only the data known then, and grades what happened next on that version alone.

Who Uses S&P 500 vs Its Long-Term Trend

Long-term investors

The gap from trend has been a guide to the following decade’s real returns: high readings came before thin decades and low readings before rich ones. The study on the page shows how strong that relationship has been, and on how few independent decades.

Allocators

The reading is a price-only view of valuation. It needs no earnings, so it cross-checks the Shiller CAPE and profit-based gauges, which can be distorted when profits themselves are unusual.

Market historians

The chart puts 1929, the 1960s and 2000 on one line with today, so you can see how the current run compares with the great extremes of the past.

Pro Tips

The start date moves the answer

A trend from 1881 and a trend from 1926 have different slopes, and today’s reading differs between them by more than fifteen points. The page shows both, because neither is the one true line.

It says nothing about timing

The market can stay above its trend for a decade, as it did from the mid-1950s to the late 1960s. The gap has been a guide to long-run returns, not to the next year.

Trust the point-in-time study

Studies graded on a full-history trend look better than they were, because the line already knows how the story ended. The forward-return table uses only the line an investor could have drawn at the time.

Common Issues & Solutions

Why real total return and not the index price?▾

Dividends were most of the stock market’s return for much of the twentieth century, and inflation varied widely. Leaving either out would make the trend line depend on the dividend policy and the inflation of each era, not on what investors earned.

Why do recent months use an estimated dividend?▾

Shiller publishes dividends a few months after prices. For those months the last known dividend yield is carried forward, which changes the index by a fraction of a percent. The page says how many months are estimated.

Is this the same as the widely shared chart of the S&P 500 against its trend?▾

It uses the same method, and from 1926 it produces nearly the same trend and reading. It adds the full record from 1881, a version without hindsight, and forward returns measured in the following decades.

Frequently Asked Questions

Is the stock market above its long-term trend?▾

Above it. As of September 2026, the real S&P 500 total return is +56.2% against its trend since 1881 and +39.6% against its trend since 1926. Readings above +30% have been reached in about a quarter of months over the record.

What is the long-term growth rate of US stocks?▾

After inflation and with dividends reinvested, the trend line through the full 145-year record grows 6.61% a year; the line fitted from 1926 grows 6.87% a year.

What returns followed readings this far above trend?▾

Using only the trend known at each date, months more than 30% above trend were followed by a median real return of 1.9% a year over the next ten years, against 7.5% for all months and 12.2% for months more than 30% below. That rests on 6 non-overlapping decades above the line, so it is a pattern and a small sample.

What is the S&P 500 trend line?▾

It is the long-run compounding path of US stocks: a straight line through the log of the inflation-adjusted S&P total-return index, which on a log scale is what steady growth at a constant rate looks like. The gap between the index and the line shows how far prices have run ahead of, or fallen behind, that path.

Why does the reading change with the start date?▾

The slope of the line depends on which years it is fitted to. The years after 1926 grew a little faster than the whole record from 1881, so the 1926 line sits higher today and the market looks less stretched against it. Both are legitimate; the page shows both.

Does being far above trend mean a crash is coming?▾

It has meant weaker long-run returns and has never given a date. Markets have stayed well above trend for years at a time. The study on the page measures what real returns followed over five and ten years, using only the trend known at each date, with the number of independent periods stated.

Where does the data come from?▾

Robert Shiller’s monthly S&P composite price, dividends and consumer prices, published at shillerdata.com and updated monthly.

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Last updated: 2026-09