The short answer
A negative mathematical price-to-earnings ratio usually comes from negative earnings per share. With a positive share price divided by a loss per share, the result is negative. Many data providers display N/A or omit the ratio instead.
That is not the same as a low positive P/E. A negative number does not establish that a stock is cheap, and a more negative number does not give you a useful ranking of bargains.
A simple example
Imagine two fictional companies, both trading at $30 per share:
| Company | Earnings per share | Calculation | Interpretation |
|---|---|---|---|
| Example A | $3 | $30 ÷ $3 = 10 | A positive P/E of 10 |
| Example B | −$2 | $30 ÷ −$2 = −15 | The company reported a loss; conventional P/E comparison is not meaningful |
Now suppose Example B’s loss narrows to $1 per share. The quotient becomes −30. The more negative number does not mean its operating situation became worse; in this example the loss actually got smaller. This is why ordering loss-making businesses by their negative multiples can mislead.
Negative and unavailable are different
N/A can mean the provider does not calculate a ratio for negative or zero earnings. It can also mean data is unavailable. You need the underlying earnings figure and the provider’s definition to distinguish those cases.
Check the reporting period and accounting basis too. A company might have a trailing loss while analysts forecast future profits. Those describe different periods, not necessarily an error. Read trailing vs forward P/E before comparing them.
Questions to investigate next
Instead of trying to “fix” the ratio, investigate the loss. Was revenue falling? Did expenses rise? Was there a large accounting charge? Is management’s explanation supported by the financial statements?
These are research questions, not a checklist that automatically makes a loss acceptable. A one-time label deserves scrutiny, and a business can keep consuming cash even while a particular adjusted measure looks better.
Compare the company’s current explanation with earlier reports. Record which assumptions would have to hold for profitability to improve. Where possible, examine the cash-flow statement and balance sheet as well as earnings.
Use the number appropriately
Our P/E calculator flags zero or negative earnings rather than presenting a negative output as a conventional valuation multiple. You can use Stocker’s company research views to explore the context around a metric, then follow through to original filings.
A missing P/E is a prompt to investigate. It is not, by itself, a reason to buy or reject a company.
Sources & further reading
Based on the sources below. Company and app information can change; check the original source before relying on it.
Stocker makes tools for discovery and research. This article is educational and is not a recommendation to buy, sell or hold any security. How we write