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Many investors are still learning about the various metrics that can be useful when analysing a stock. This article is for those who would like to learn about Return On Equity (ROE). To keep the lesson grounded in practicality, we'll use ROE to better understand Yorkey Optical International (Cayman) Ltd. (HKG:2788).

Over the last twelve months Yorkey Optical International (Cayman) has recorded a ROE of 7.6%. Another way to think of that is that for every HK$1 worth of equity in the company, it was able to earn HK$0.076.

Check out our latest analysis for Yorkey Optical International (Cayman)

How Do You Calculate ROE?

The formula for ROE is:

Return on Equity = Net Profit ÷ Shareholders' Equity

Or for Yorkey Optical International (Cayman):

7.6% = US$7.7m ÷ US$101m (Based on the trailing twelve months to December 2018.)

Most readers would understand what net profit is, but it’s worth explaining the concept of shareholders’ equity. It is the capital paid in by shareholders, plus any retained earnings. The easiest way to calculate shareholders' equity is to subtract the company's total liabilities from the total assets.

What Does Return On Equity Signify?

ROE measures a company's profitability against the profit it retains, and any outside investments. The 'return' is the profit over the last twelve months. That means that the higher the ROE, the more profitable the company is. So, all else being equal, a high ROE is better than a low one. That means ROE can be used to compare two businesses.

Does Yorkey Optical International (Cayman) Have A Good Return On Equity?

Arguably the easiest way to assess company's ROE is to compare it with the average in its industry. Importantly, this is far from a perfect measure, because companies differ significantly within the same industry classification. If you look at the image below, you can see Yorkey Optical International (Cayman) has a lower ROE than the average (9.8%) in the Electronic industry classification.

That certainly isn't ideal. We'd prefer see an ROE above the industry average, but it might not matter if the company is undervalued. Nonetheless, it could be useful to double-check if insiders have sold shares recently.

Why You Should Consider Debt When Looking At ROE

Companies usually need to invest money to grow their profits. The cash for investment can come from prior year profits (retained earnings), issuing new shares, or borrowing. In the case of the first and second options, the ROE will reflect this use of cash, for growth. In the latter case, the use of debt will improve the returns, but will not change the equity. That will make the ROE look better than if no debt was used.

Combining Yorkey Optical International (Cayman)'s Debt And Its 7.6% Return On Equity

One positive for shareholders is that Yorkey Optical International (Cayman) does not have any net debt! So although its ROE isn't that impressive, we shouldn't judge it harshly on that metric, because it didn't use debt. After all, when a company has a strong balance sheet, it can often find ways to invest in growth, even if it takes some time.

The Key Takeaway

Return on equity is useful for comparing the quality of different businesses. Companies that can achieve high returns on equity without too much debt are generally of good quality. If two companies have the same ROE, then I would generally prefer the one with less debt.

Having said that, while ROE is a useful indicator of business quality, you'll have to look at a whole range of factors to determine the right price to buy a stock. Profit growth rates, versus the expectations reflected in the price of the stock, are a particularly important to consider. So I think it may be worth checking this free this detailed graph of past earnings, revenue and cash flow .

But note: Yorkey Optical International (Cayman) may not be the best stock to buy. So take a peek at this free list of interesting companies with high ROE and low debt.

We aim to bring you long-term focused research analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material.

If you spot an error that warrants correction, please contact the editor at editorial-team@simplywallst.com. This article by Simply Wall St is general in nature. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. Simply Wall St has no position in the stocks mentioned. Thank you for reading.