2 Important Ratios You Should Look at Before Buying Any Stock

Canadian National Railway (TSX:CNR)(NYSE:CNI) is a great example of a stock that trades at very modest multiples and that could be a solid investment to make today.

| More on:

Valuations for a stock can get out of control sometimes. However, over the long term, investors can expect to see things stabilize and return to more normal levels.

A good example of this is the cannabis industry, where valuations have often become obscene, with promises of future growth being enough for many investors to forgive many other shortcomings, including poor market share and little hope for profitability in the imminent future.

It’s not surprising that we’ve seen some of those highly priced stocks fall in value recently. Investors can, however, protect themselves from big corrections in share price by simply taking a look at a couple of important ratios that will quickly help identify if there is a problem with a stock’s value.

Price-to-earnings ratio

The first ratio is a very common one, price-to-earnings (P/E). It’s an easy one to calculate and serves as a very good benchmark when comparing other companies.

It is calculated by taking the current stock price and dividing it by the earnings per share (EPS) that the company has generated over the past four quarters.

As it involves price, it has the opportunity to fluctuate very quickly, but can help you make a quick assessment of whether a stock is overpriced or not.

Let’s look at Canadian National Railway (TSX:CNR)(NYSE:CNI) as an example. Over the past four quarters, the company has generated profits of $4.4 billion.

If we divide that by 725 million shares, that gives us an EPS of a little over $6.1. With the stock price around $124, its P/E is a little more than 20.

Value investors might sometimes target a P/E that’s 15 or less, although 20 isn’t a very high multiple, especially since CN Rail has shown some good growth over the years.

Generally, a P/E of 15 or less is most suitable for stocks that don’t have a lot of growth. Tech stocks may often trade at 30 times their earnings, or even higher.

But if you see a stock that’s trading more than 100 times its earnings, it’s something that warrants further investigation. It could be that the company has had a bad quarter dragging down its numbers over the past year, or it could be a sign that the stock has simply gotten too expensive.

If a company doesn’t have any earnings, then obviously a P/E ratio won’t be very helpful. This is where we can move on to the next multiple:

Price-to-sales multiple

Using a price-to-sales (P/S) multiple is another valuable tool in assessing value. This calculation involves taking the company’s market cap and dividing it by its sales over the past year.

If we go back to CN Rail, the stock has a value of around $89 billion. And over the past four quarters, sales have totaled $15 billion. This tells us that CN Rail’s P/S ratio is at around 5.9.

There’s a lot more variability here as to what’s acceptable, but generally, if you’re under a P/S of 10 then that’s good. Ideally, however, you’d like to see the multiple as low as possible.

Here again, it would’ve helped flag high-flying cannabis stocks that were trading more than 100 times their sales.

Bottom line

These multiples can help you get an idea of how much of a premium you’d be paying to own a stock today. It’s also helpful when comparing similar investments.

Ultimately, there are many other ways you can assess a company’s value, but these two ratios can, at a minimum, help you identify stocks which are grossly overvalued based on their recent performances.

Fool contributor David Jagielski has no position in any of the stocks mentioned. CN is a recommendation of Stock Advisor Canada.

More on Dividend Stocks

Retirees sip their morning coffee outside.
Dividend Stocks

Retiring? $1 Million Isn’t Enough Anymore

$1,000,000 invested in iShares S&P/TSX 60 Index Fund (TSX:XIU) doesn't provide enough income to retire on.

Read more »

dividends grow over time
Dividend Stocks

Got $10,000? This Dividend Stock Could Deliver $44.26 a Month in Passive Income

You can turn $10K into an easy $44.26/month passive-income stream with this rock-solid Canadian REIT that's raised its payout for…

Read more »

Printing canadian dollar bills on a print machine
Dividend Stocks

Transform Your TFSA Into a Cash-Creating Machine With $10,000

These two monthly dividend stocks can deliver stable, reliable passive income.

Read more »

shopper checks her receipt
Dividend Stocks

Canadians Are Spending More Carefully. This Retail Stock Is Built for It.

Here's a retailer that can keep growing even when consumers get cautious.

Read more »

man touches brain to show a good idea
Dividend Stocks

The Smartest Way to Invest $10,000 in Your TFSA Right Now

Unlock tax-free dividend income in your self-directed investment portfolio by allocating a portion of your TFSA to hold these two…

Read more »

drinker sniffs wine in a glass
Dividend Stocks

Inflation Just Hit 2.4%: 3 Canadian Dividend Stocks Built to Hold Up

Investors will want to own companies that can survive even when costs rise.

Read more »

Woman in private jet airplane
Dividend Stocks

One TSX Dividend Stock That Might Have More Upside in 2026 Than Most People Expect

Discover how dividend cuts can impact stocks and why some companies slash dividends to strengthen their financial health.

Read more »

Canadian Dollars bills
Dividend Stocks

5 TSX Dividend Stocks With Solid Yields Built for Steady Cash Flow in Any Market

These TSX dividend stocks have solid yields and backed by businesses that generate steady cash flow in any market.

Read more »