Key Financial Ratios Every Investor Should Understand Before Buying Individual Shares

“Financial ratios cannot predict future performance, but they help investors ask better questions about a company’s valuation, profitability and long-term sustainability.”

The growing popularity of retail investing has encouraged more individuals to buy shares directly in listed companies rather than investing solely through diversified funds. High-profile stock market listings have further accelerated this trend, prompting many first-time investors to consider building their own portfolios.

While investing in individual companies offers the potential for higher returns, it also carries greater risk. Unlike diversified investment funds, which spread capital across dozens or even hundreds of companies, purchasing individual shares concentrates exposure to the performance of a relatively small number of businesses. As a result, careful research becomes essential before committing capital.

Investment specialists advise that prospective shareholders should assess a company’s financial position, profitability, valuation and balance-sheet strength rather than relying solely on market sentiment or recent share price performance. Although financial metrics cannot guarantee future returns, they provide valuable insights into a company’s operational health and help investors identify potential strengths and weaknesses.

Jemma Slingo, pensions and investment specialist at Fidelity International, says financial data enables investors to ask informed questions, including whether a company’s shares appear fairly valued and whether current shareholder returns are likely to be sustainable. She also cautions that historical performance should never be viewed as a reliable indicator of future results.

One of the most widely used valuation measures is the price-to-earnings (P/E) ratio. This compares a company’s current share price with its earnings per share and indicates how much investors are willing to pay for each pound of profit generated by the business.

A relatively high P/E ratio may suggest investors expect strong future earnings growth, while a lower ratio can indicate that shares appear comparatively inexpensive. However, valuation should always be considered alongside companies operating in the same industry, as acceptable P/E ratios vary significantly between sectors.

Another commonly used measure is the price-to-book (P/B) ratio, which compares a company’s market value with its book value, representing the net value of its assets after liabilities have been deducted.

A P/B ratio below one has traditionally suggested that a company may be undervalued, although investment professionals emphasise that interpretation depends heavily on sector-specific circumstances. Banking is one industry where the ratio is frequently monitored because bank assets and liabilities are generally easier to value than those of many other businesses.

According to investment specialists, the banking sector experienced a significant market revaluation during late 2023 and early 2024. As a result, several major UK banks now trade at price-to-book ratios above one, reflecting sustained improvements in investor confidence and share prices.

Profitability is another key area investors examine. One of the most important measures is return on equity (ROE), which assesses how efficiently management generates profits from shareholders’ invested capital.

ROE is calculated by dividing a company’s net income by shareholders’ equity. A higher percentage generally indicates that management is using invested capital effectively, although the benchmark for strong performance differs across industries.

Lee Wild, Head of Equity Strategy at Interactive Investor, notes that many investment resources identify an ROE between 15% and 20% as favourable. However, he advises comparing companies with competitors operating within the same sector rather than relying on universal benchmarks.

Tina Cook, Senior Equity Analyst at Raymond James, points to technology group Halma as an example of consistent profitability, noting that the company has recorded an average return on equity of approximately 17% over the past five years.

Investment professionals also stress that ROE should not be viewed in isolation. Companies carrying higher levels of debt may report stronger returns on equity because borrowing increases financial leverage.

For that reason, analysts recommend reviewing the debt-to-equity (D/E) ratio alongside ROE. The debt-to-equity ratio compares a company’s total liabilities with shareholders’ equity and provides an indication of how heavily operations depend on borrowed funds.

A relatively high debt-to-equity ratio may increase financial risk, particularly during periods of higher interest rates or weaker economic conditions, while lower borrowing generally provides greater financial flexibility.

Income-focused investors frequently pay close attention to dividend yield, another widely used measure when evaluating listed companies.

Dividend yield shows the annual cash dividend paid to shareholders as a percentage of the current share price. It is calculated by dividing the annual dividend per share by the current market price and multiplying the result by 100.

A high dividend yield can make a company attractive to investors seeking regular income. However, investment specialists caution that unusually high yields may also indicate potential problems. If a company’s share price has fallen sharply while its dividend remains unchanged, the resulting yield may appear attractive despite concerns about future profitability or dividend sustainability.

Analysts therefore recommend examining whether dividend payments are supported by consistent earnings and healthy cash flow rather than focusing solely on headline yields.

Experienced investors generally rely on several financial indicators rather than a single metric when evaluating investment opportunities. Valuation measures, profitability ratios, balance-sheet strength and dividend policies each provide different perspectives on a company’s financial condition.

These figures should also be considered alongside broader factors including competitive position, management quality, industry trends, regulatory developments and long-term growth prospects.

Ultimately, financial ratios are tools designed to support informed decision-making rather than predict future share price movements. Used together, they help investors assess whether a business appears financially resilient, appropriately valued and capable of delivering sustainable returns over the long term.