# S&P 500 forward P/E at 21 versus trailing 28 signals high earnings

**Published:** 2026-07-10T20:48:15.458Z  
**Topic:** Stock Market  
**Sentiment:** neutral  
**Publisher:** TrendWatcher — https://www.trendwatcher.in/article/a7014316-b3e8-49b9-91c8-0844ca124c30

S&P 500 forward price‑earnings ratio 21 vs trailing 28 shows market relies on strong near‑term earnings; learn why analysts warn of a rare valuation spread and

The S&P 500 is trading at a forward price‑earnings (P/E) ratio of 21, well below its trailing P/E of 28, a spread that historically only appears at market extremes such as the year 2000【1】.  
This gap implies investors are betting on unusually strong earnings growth over the next 12 months, a scenario that has materialized in fewer than one in five quarters since 1989【1】.  

| At a glance | |
|---|---|
| Forward P/E (12‑mo) | 21 |
| Trailing P/E (LTM) | 28 |
| Historical spread rarity | Only seen at extremes like 2000 |
| Earnings growth implied | >8% annual growth, rare outside post‑recession rebounds |

## Why the spread matters  
The forward P/E uses the same price numerator as the trailing P/E, so the difference reflects the gap between last‑twelve‑month (LTM) earnings and next‑twelve‑month (NTM) earnings expectations【1】. Professors Aswath Damodaran and Itzhak Ben‑David explain that the spread is essentially a direct measure of expected earnings growth, and that such a wide gap has historically coincided with periods of earnings rebounds after sharp declines (1994‑95, 2003‑04, 2009‑11, 2021‑22)【1】.  

## Analyst forecasts and valuation risk  
Ben‑David notes that forward P/E looks “reasonable” only because it incorporates earnings that have not yet occurred, and past episodes with a similarly wide spread ended with earnings disappointments, multiple‑year valuation compressions, or both【1】. A 2024 working paper with Alex Chinco found that analysts often set price targets by applying trailing P/E multiples to forecast earnings, effectively restating optimism rather than providing an independent valuation check【1】. Additional research by Gao and Wu (2008) suggests trailing P/E outperforms forward P/E in predicting future growth, reinforcing the view that a low forward P/E does not guarantee cheapness【1】.  

## What to watch  
- **Q2 earnings season**: Corporate results and forward guidance starting next week will reveal whether earnings can meet the aggressive forecasts embedded in the forward P/E spread【1】.  
- **Analyst revisions**: Any downward adjustments to earnings forecasts could narrow the spread and trigger a market pullback, as seen in prior episodes.  
- **Historical valuation benchmarks**: The cyclically adjusted price‑earnings (CAPE) ratio, which averages a decade of inflation‑adjusted earnings, remains high and may signal overvaluation despite the low forward P/E【1】.  

The key question remains whether companies can deliver the near‑term earnings surge that the current forward P/E assumes; a failure would likely compress valuations and test the market’s resilience.

## Sources
1. Finznest — [The stock market looks pretty cheap based on future earnings ...](https://www.finznest.com/blog/the-stock-market-looks-pretty-cheap-based-on-future-earnings-expectations-dont-be-fooled/)
2. CNBC — [The stock market looks pretty cheap based on future earnings expectations. Don't be fooled](https://www.cnbc.com/2026/07/10/the-stock-market-looks-pretty-cheap-based-on-future-earnings-expectations-dont-be-fooled.html)

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Cite as: TrendWatcher, "S&P 500 forward P/E at 21 versus trailing 28 signals high earnings", https://www.trendwatcher.in/article/a7014316-b3e8-49b9-91c8-0844ca124c30