No one can tell you for certain whether now is the perfect time to buy.

In the short run, the share market can seem like a random place. It can be up 2% one day, down 3% the next. There’s often no rhyme or reason (although pundits are paid the big bucks for the evening news to make you think they have a crystal ball).

In this article, we’ll go step-by-step through two basic valuation tools you can use to value a share like WBC or even Bank of Queensland Limited (ASX: BOQ) and National Australia Bank Ltd (ASX: NAB).

Price-earnings (PER) analysis

The price-earnings ratio or ‘PER’ compares a company’s share price (P) to its most recent full-year earnings per share (E). Remember, ‘earnings’ is just another word for profit. Hence, the ‘P/E’ ratio is simply comparing share price to the most recent full-year profit of the company. Some experts will try to tell you that ‘the lower PE ratio is better’ because it means the share price is ‘low’ relative to the profits produced by the company. However, sometimes shares are priced to perfection for a reason!

Secondly, some extremely successful companies have gone for many years (a decade or more) and never reported an accounting profit — so the PE ratio can’t be used to value them.

Therefore, we think it’s beneficial to dig deeper than simply looking at the PE ratio and thinking to yourself ‘if it’s below 10x, I’ll buy it’.

One of the basic ratio models analysts use to value a bank share is to compare the PE ratio of the bank/share you’re looking at with its peer group or competitors and try to determine if the share price is overvalued, or undervalued relative to the average. From there, and using the principle of mean reversion, we can multiply the profits/earnings per share by the sector average (E x sector PE) to reflect what an average company would be worth. It’s like saying, ‘if all of the other stocks are priced at ‘X’, this one should be too’.

If we take the WBC share price today ($30.03), together with the earnings (aka profits) per share data from its 2023 financial year ($1.95), we can calculate the company’s PE ratio to be 15.4x. That compares to the banking sector average PE of 16x.

Next, take the profits per share (EPS) ($1.95) and multiply it by the average PE ratio for WBC’s sector (Banking). This results in a ‘sector-adjusted’ PE valuation of $30.98.

A more reliable way to value the WBC share price

The dividend discount model or DDM is different from ratio valuation like PE because the model makes forecasts into the future, and uses dividends instead of profit. Because the banking sector has proven to be relatively stable with regards to share dividends, the DDM approach can be used. However, we would not use this model for, say, technology shares which are more growth focused.

Basically, we need only one input into a DDM model: dividends per share. Then, we make some assumptions about the yearly growth of the dividend (e.g. 2%) and the risk level of the dividend payment (e.g. 7%). We’ve used the most recent full year dividends (e.g. from last 12 months or LTM) then assumed the dividends remain consistent but grow slightly.

To do the valuation, use this formula: Share price = full-year dividend / (risk rate – dividend growth rate). It’s a good idea to do the calculation using a few different growth and risk assumptions, then take the average valuation. This helps to account for some of the uncertainty.

To make this DDM easy to understand, we will assume last year’s dividend payment ($1.42) goes up at a fixed rate each year.

Next, we pick the ‘risk’ rate or expected return rate. This is the rate at which we discount the future dividend payments back to today’s dollars. The higher the ‘risk’ rate, the lower the share price valuation.

We’ve used a blended rate for dividend growth and a risk rate between 6% and 11%, then got the average.

This simple DDM valuation of WBC shares is $27.07. However, using an ‘adjusted’ dividend payment of $1.68 per share, the valuation goes to $30.11. The expected dividend valuation compares to Westpac Banking Corp’s share price of $30.03. Since the company’s dividends are fully franked, you might choose to make one further adjustment and do the valuation based on a ‘gross’ dividend payment. That is, the cash dividends plus the franking credits (available to eligible shareholders). Using the forecast gross dividend payment ($2.40), our valuation of the WBC share price forecast to $43.02.

Is this WBC valuation reasonable?

Make sure you don’t forget that the two models used here are only the starting point of the process for analysing and valuing a bank share like WBC.

We think it’s good practice to read at least three years of annual reports, jot down your thoughts/research and set out your thesis/expectations based on what management is saying. Indeed, a very useful tool is studying management’s language in presentations and videos. Is the management team candid? Or does he/she use lots of jargon and never answer a straight question? Finally, read articles and research from good analysts, and when you do, seek out people who disagree with you. These voices are often the most useful.

These are just a handful of the best strategies to use alongside your valuation tools to determine if you’re making a mistake — hopefully, before you make a costly mistake!