The Return on Assets (ROA) formula is an important tool for traders in the Forex market. It is used to measure the profitability of a trading system by comparing the total revenue generated by the system with the total amount of money invested. The formula requires traders to divide the total net income of a trading system by the total amount of money that has been invested. The resulting figure gives the trader a return percentage based on the amount of money that has been invested in the system. Knowing the return percentage enables traders to compare the profitability of different systems, allowing them to make smarter decisions when selecting their trading strategy.