The future gain or loss of income from a capital investment is referred to as the "return on investment" (ROI). It is a measure of the profitability of an investment and is typically expressed as a percentage of the initial investment. ROI takes into account both the amount of money gained or lost and the time frame over which the investment was held. A positive ROI indicates that the investment generated more money than was initially invested, while a negative ROI indicates that the investment lost money. ROI is an important metric used in finance and investment analysis to evaluate the success of an investment and to compare different investment opportunities.