The study analyzes the financial performance of four major UK retail companies: Tesco, Sainsbury, Aldi, and Lidl, using various financial ratios to assess their stability and competitiveness. It highlights how the COVID-19 pandemic affected their financial health, particularly in 2020, leading to significant losses for Tesco and Sainsbury. The researchers emphasize that ratio analysis is crucial for understanding a company's financial position and guiding investors in their decision-making processes.