Dissecting the PE Ratio Formula:
The technical definition of the PE ratio formula is as follows:
P/E Ratio = Price of a Share / Earnings per Share
Just to let you know, the PE ratio is often written as “P/E ratio” or just “P/E”. It is also sometimes called the “price multiple” or “earnings multiple”.
Let’s do a quick example using the stock for AT&T:
According to this screen shot from Yahoo Finance:
- Current Price = $35.68
- Earnings per Share (EPS) = $1.29
- Therefore, the P/E = $35.68 / $1.29 = ~27.66 (this does not match the number given on Yahoo exactly due to rounding of significant figures)
Remember that the price of a stock changes every minute as investor demand and supply dictates its increase and decrease in value.
The earnings portion of the equation tends to remain for static and can be based on one of the following:
- Trailing PE: Uses the recorded earnings per share from the last four quarters. This is the way that the P/E ratio is most commonly reported and what you find in most financial articles.
- Forward PE: Uses the expected earnings per share from the upcoming next four quarters based on analyst and company predictions.
- Current PE: Uses a combo of the past two quarters and expected two quarters EPS.
A side-note on earnings: Companies can use different accounting methods and tax rules to manipulate their earnings. Just be aware that sometimes you may not always be comparing apples to apples when it comes to earnings reports.
What Does the P/E Ratio Mean?
So why the love for this metric specifically? Investors can use the PE ratio as a way to gauge the appreciation in value for the shares of a company. A high or low number can reveal whether a company is currently under-valued or over-valued.
Let’s think of it this way:
The “Selling My Blog” Example:
Suppose my blog My Money Design became its own company. And let’s say this blog was making $10,000 per year. Now suppose you offered $50,000 to buy it.
That would be a PE Ratio = $50K / $10K = 5.0
So what if I had asked a price of $100,000 to buy my blog?
That would be a PE Ratio = $100K / $10K = 10.0
Which would you rather spend: $50K or $100K? That’s the difference between in PE ratio formula of 5.0 and 10.0.
So in this instance, a lower PE ratio would look more attractive. But is this always the case?
I’m afraid not. Remember that a price becomes the price only when someone is willing to buy it for that amount. I cannot emphasize this enough; and not just in personal finance.
Suppose I really wanted $100K for my blog but all I was able to get was $50K. That would mean that potential buyers may not have a lot of optimism about the future of my blog. Likewise, if someone was willing to give me $100K no problem, then perhaps that buyer does have a lot of confidence in the future of my blog and its ability to make earnings. So in this case, a higher PE ration would look more attractive.
AT&T Example Again:
Let’s go back to our AT&T stock example and use a real company to see how this works.
T has a P/E of 27.5. In general that sounds kind of high. So why is that?
Its current EPS is $1.29. If we fast-forward one year, we’ll see that the expected EPS is equal to $2.51. So as you can guess, the price is high because investors are expecting to have an increase in EPS over the course of the year. That investor confidence fuels a higher price which then goes through the PE ratio formula to yield a higher number.
Notice that the forward P/E is lower than it is now at 13.17. Should you be worried? No, this shows that if the price of the stock stayed exactly the same as it is now, then the P/E value would be lower since the earnings would be higher. Do you really think the price will stay the same a year from now? That’s incredibly doubtful. The reason companies even publish this value is to demonstrate to investors that there might be a good opportunity to buy.
What’s a Good PE Ratio?
That’s a loaded question …
Probably the most value from looking at the PE ratio comes from comparing stocks against their own historical data or with other stocks inside the same industry. For example: Comparing the PE ratios of a stock from Communication versus Technology would not gain the most value.
To give you some idea of where to start, the historical PE ratio of the median stock in the S&P 500 Index is approximately equal to 15.
Conclusions:
So to sum everything up, here’s what the PE ratio formula can tell us:
A high P/E Ratio can indicate that:
- Investors are expecting higher earnings growth in the future.
- The price may be driven up too high and the company may be over-valued.
- Sellers are holding out longer and not releasing as many shares into the market.
- Earnings for this company may be higher than normally, and it may possibly be hard to keep up with or sustain.
A low P/E Ratio can indicate that:
- Investors are expecting lower earnings growth in the future.
- The company may be under-valued due to its low price.
- The company has reached a state of mature earnings.
- The company is experiencing some inconsistent earnings.
No PE Ratio:
- This just means that the company has no earnings. Think about what happens when a company isn’t making any money? Mathematically we can’t divide by zero. So in this case we say they don’t have a PE Ratio.
The fundamental lesson: You can never really just look at the number alone and make a black/white conclusion. Always consider other factors that may attribute as to WHY the value is higher or lower. All stock metrics should always be used in conjunction with one another to tell the whole story.
Disclaimer: I own shares of T.
Readers: How often do you pay attention to the PE ratio when making decisions about your stock prospects?
Related Posts:
- Using the Dividend Yield Formula to Evaluate a Stock Prospect
- Can the Dividend Payout Ratio Help You Pick a Good Stock?
- Rethinking My Strategy for What Stocks to Buy This Year
Image courtesy of FreeDigitalPhotos.net
I like the P/E ratio, but I personally think that the Price/Free Cash Flow is a better metric as to the health of the company.
There are certainly a lot of other (and perhaps better) metrics to use for evaluation. The ROA is my favorite because it takes the price right out of the equation. But like all things, you have to consider several of them together.
You breakdown the P/E ratio very well. I never really got it until this post but I still say I don’t use it too much. Stocks like you stated are only worth what people are willing to pay. I have seen stocks I thought no one would buy with horrible P/E ratios make people some serious cash. It just all depends on what the markets “feel” like. Emotions weigh heavy when buying and selling happens.
The market can be very fickle, and sometimes it defies common sense. That can be disastrous if you follow it too closely or a blessing if you are looking for golden opportunities to snatch up what others are too afraid to do.
Interesting consideration with that hypothetical–will keep in mind in the near future.
Good overview of the PE ratio, but it’s a subject for a whole new post as to the relevance of the metric. I’ve always wondered why it gets so much love when earnings are so easily manipulated. I’m not sure we’ll see much price appreciation though from AT&T because the TTM EPS are the number that’s out of line, not the forward EPS.
I’m not sure either why it gets so much attention. Price is fickle, and earnings as we know can be misrepresented or overstating when looking forward. My personal preference is to look at metrics that ignore price altogether and focus more on the fundamentals of the company.
I’m not trying to carp about a potential typo, but I am curious: did you mean “understating” or “understanding”? Given your emphasis on SEO, it makes me wonder whether the wording of the title was deliberate in some clever way.
Wow! Thanks a ton for pointing out that dumb mistake. I really need an editor. And to stop writing posts at night …
YOu have to start somewhere when you look at a stock, and IMHO the PE ratio is the place to start. It sets the table, so to speak, for what follows.
What I’ve found to be revealing is an extension of the PE ratio, the PEG ratio, which combines the growth of the company with the PE ratio. It helps that the PEG ratio has a dividing line of 1. Over 1 means investors may be anticipating more growth, while below 1 may indicate a possible growth bargain…
I prefer metrics like cash flow/ share to PE. You can manipulate earnings and buy back shares to manipulate PE.
Nonetheless, you can get an idea of a stocks relative valuation by benchmarking its current PE with past PE.