Warren Buffett rarely invests in tech stocks because he often does not understand them, which is outside his area of expertise. Unless an investor understands a company's business model and the drivers of future growth, they risk being blindsided. Fundamental analysis attempts to determine a company's value by focusing on internal factors like finances, management, and products, as well as external factors such as the economy and interest rates, to evaluate growth potential and investment risk. Performing various financial ratio calculations and comparing them over time and between competitors can provide important insights for fundamental investors.