Monitoring the Annual Percentage Rate helps traders assess the full cost of borrowing or the potential return on investment. A lower APR on borrowed funds reduces the overall expense of leveraged trades, improving profitability. Understanding APR also allows traders to identify cost-effective borrowing opportunities and maximize returns on investments. Keeping track of APR ensures that traders maintain a balanced cost-benefit approach, ultimately enhancing their financial decision-making and portfolio performance. Compare APRs across brokers to find the most cost-effective borrowing options.