S&P 100 Trailing P/E

## What this measures

How much investors are paying for each dollar the largest U.S. companies already earn: the combined market value of the S&P 100 divided by the companies' combined net income over the last four reported quarters, as known on each day.

## Why it matters

Price-to-earnings is the most common test of whether stocks are expensive. This version is built only from public filings and prices, so every input can be checked.

## How to read it

A reading of 25 means the group is valued at 25 times a year of its profits. Companies with losses count, as they do in published index P/E ratios, which pulls the ratio up. Read beside the median company P/E (equities.sp100.median_trailing_pe): when this reading is well above the median, a few very large, highly valued companies are lifting it.

## What it does not say

It is not a forward P/E: analysts' estimates of next year's earnings are licensed data Palanor does not carry. Earnings are reported GAAP net income, so one-off gains and charges move it. It uses today's S&P 100 members and current share counts back in time. A day is published only when at least 90% of the companies have both a price and a full year of reported earnings.

## Source

Net income from company filings with the SEC (XBRL, public domain). Share prices received through a licensed market data provider. Ratio computed by Palanor.