The CAPE earnings yield minus the ten-year real interest rate — what stocks yield over bonds after inflation, on Shiller’s own convention. Low is expensive.
Low ECY = expensive — the inversion is the point of this lens.
The zero line is absolute: below it, bonds out-yield stocks. One period in the computed record — May 1999 → November 2000.
| the period | S&P +1y from the crossing | S&P +3y |
|---|---|---|
| May 1999 → Nov 2000 · 19 months below zero | +11.9% | −20.3% |
One period in the computed record. A named state, not a timing signal. The windows open the month the crossing month's reading was published, with its CPI.
| tier | periods | S&P med +1y | med +3y | worst +3y |
|---|---|---|---|---|
| deep red — thin vs bonds TODAY | 9 | +12.8% | +26.7% | −8.9% |
| pale red | 25 | +12.2% | +30.6% | −30.5% |
| neutral | 14 | +15.6% | +52.0% | −19.6% |
| pale green | 8 | +14.6% | +54.8% | +17.0% |
| deep green — wide vs bonds | 7 | +18.8% | +50.0% | +21.0% |
Counts and medians of the collapsed register — the same periods listed below; medians are records, not rankings (the one-year and three-year columns do not order the same way). Low ECY = expensive: the red rungs are the thin-margin states.
| tier | months | share | longest period |
|---|---|---|---|
| deep red — thin vs bonds | 150 | 19.7% | 30m (1996-03..1998-08) |
| pale red | 115 | 15.1% | 9m (2025-05..2026-02) |
| neutral | 392 | 51.4% | 108m (2009-05..2018-04) |
| pale green | 61 | 8% | 23m (1975-03..1977-01) |
| deep green — wide vs bonds | 44 | 5.8% | 15m (1977-02..1978-04) |
Shares of the 762 post-stabilization months (Mar 1963 → today), each month ranked only against the months before it — the expanding-window rule; the shares move as history accrues.
| entry | tier | ECY | pct | months | S&P +1y | S&P +3y |
|---|---|---|---|---|---|---|
| Apr 2026 | pale-red | +1.66 | p23 | 5 | open | open |
| May 2025 | pale-red | +1.49 | p17 | 10 | +25.0% | open |
| Oct 2024 | pale-red | +1.52 | p17 | 6 | +15.1% | open |
| Aug 2024 | neutral | +1.82 | p26 | 2 | +18.5% | open |
| Feb 2024 | pale-red | +1.65 | p20 | 6 | +11.4% | open |
| Dec 2023 | neutral | +1.95 | p28 | 2 | +26.1% | open |
| Sep 2023 | pale-red | +1.75 | p24 | 3 | +37.9% | +89.2% |
| Nov 2018 | neutral | +1.92 | p29 | 58 | +26.2% | +91.7% |
| May 2018 | pale-red | +1.73 | p24 | 6 | +7.0% | +62.5% |
| May 2009 | neutral | +5.51 | p71 | 108 | +19.5% | +51.8% |
Periods of at least two consecutive months in a tier (the VE convention); the raw monthly census — 86 boundary events, 23 lasting a single month — is disclosed on the methodology page. Each period's S&P windows open the month its first reading was published — a month's ECY is known when that month's CPI is, about two weeks after the month.
Shiller’s convention reads the ten-year real rate at 1.60% this month, and the market’s TIPS read averages 2.64%. The convention sits −1.04 points below the market, because the 2021–22 inflation burst still rides inside its trailing ten-year window. On the market’s real rate, today’s ECY would be thinner still.
Latest-basis, labeled: the CAPE leg revises, and readings shown are today’s revised history. October 2025 has no reading — the BLS published no CPI for that month; this site publishes only observations that exist. Shiller’s convention real rate (GS10 minus trailing ten-year CPI inflation, his file’s own arithmetic) is shown beside the market’s TIPS read; the two are different instruments and their gap is stated, not reconciled. Counts, never probabilities; descriptive record, never a forecast. As of: CAPE 2026-10-31 · GS10 2026-10-01 · displayed month 2026-09. How it's measured →