# P/E ratio (TTM) > The P/E ratio is a stock's price divided by its earnings per share over the trailing twelve months, or how many years of current profit the market is paying for. It is undefined for companies whose trailing earnings are negative. Canonical: https://patternsradar.com/learn/pe-ratio [Fundamentals](https://patternsradar.com/learn.md) · field `pe` divides the day's close by `eps_ttm`, the sum of the last four filed quarterly profits per share as known on that date. The earnings side updates when a result is filed and the price side updates every session, so the ratio moves daily: a stock re-rates from 20 to 25 times without any change in earnings if the price rises a quarter. When the trailing twelve months show a loss the field is NULL rather than negative. A loss-maker has no P/E, and a scan on `pe < 15` will never match it, which is the intended behaviour. The ratio is used as a price-of-quality test rather than a signal in itself. `pe < 15 and close > sma(200)`, the Low P/E in an uptrend scan, is the value-with-confirmation form: cheap on trailing earnings and being re-rated, rather than cheap and forgotten. The Quality compounders scan uses a P/E ceiling the other way round, to exclude growth the market has already paid up for. `pe between 10 and 25` with an earnings-growth condition is the standard growth-at-a-reasonable-price shape. The caveats are the ones every trailing multiple carries. Trailing earnings include one-offs: an asset sale or writeback inflates EPS and makes the stock look cheap for four quarters, while a one-time charge does the opposite. The comparison only means something within a sector, since banks, IT services and capital-goods companies trade on structurally different multiples, and a low P/E across the whole market is mostly a list of cyclicals at a peak-earnings moment. A stock appears only once four quarters are on file, so recent listings are absent. Its siblings are the earnings-growth fields. `profit_growth_yoy` and `revenue_growth_yoy` compare the latest quarter to a year earlier, and the `profit_cagr_*` family measures multi-year compounding. P/E answers what you pay and those answer what you get for it, which is why most fundamental scans need both legs. ## In Sift Written as `pe — price ÷ trailing-twelve-month EPS; eps_ttm — the earnings per share it is built on`. A working scan, Stocks on a moderate trailing multiple that are holding above their 200-day average: ```sift where pe between 10 and 25 and close > sma(200) ``` 1 of the 500 most-traded NSE stocks match today, as of 30 Sept 2026. ## Scans that use it Prebuilt scans in the library whose query reads this value. Each carries a hit-rate replay over the last 250 sessions. - [Low PE in an uptrend](https://patternsradar.com/screener/low-pe-uptrend.md): Under fifteen times trailing earnings and above the 200-day average. Cheap, and no longer ignored. - [Quality compounders](https://patternsradar.com/screener/quality-compounders.md): Profit compounding above 15% a year for five years, under 30 times earnings, interest costs up less than 5%, financials excluded. ## Common questions ### What is a good P/E ratio? It depends entirely on the sector and the growth rate. Fifteen is cheap for an IT services company and ordinary for a public-sector bank; forty is expensive for a cement maker and routine for a consumer brand. Compare a stock with its own history and its peers, and pair the multiple with an earnings-growth condition so that cheap does not simply mean shrinking. ### Why does a loss-making company have no P/E? Because the ratio divides by earnings, and negative earnings produce a negative multiple that means nothing: a company losing more money would show a P/E closer to zero. The field is NULL when trailing-twelve-month earnings are negative, so such stocks are excluded from any P/E condition instead of being ranked as the cheapest. ## Related terms [Promoter holding](https://patternsradar.com/learn/promoter-holding.md), [Market capitalisation](https://patternsradar.com/learn/market-cap.md), [Dividend yield](https://patternsradar.com/learn/dividend-yield.md). --- Price and delivery data from the [eod2](https://github.com/BennyThadikaran/eod2) dataset: National Stock Exchange of India end-of-day files, split- and bonus-adjusted, updated after each close. Not affiliated with or endorsed by NSE. PatternsRadar is a research tool. Nothing here is investment advice or a recommendation to buy or sell anything.