Consider an investment portfolio structured with a target asset allocation of 60% stocks and 40% bonds. Over a year, the portfolio's stocks appreciate significantly by 25%, while the bonds yield a modest 5% increase. At year's end, the total value of the portfolio is $1,000,000.
Given the rise in asset values, the new proportions of the assets will have changed, potentially necessitating a rebalancing of the portfolio to maintain the original asset allocation. Which of the following describes the most appropriate reason for rebalancing the portfolio to its original allocation?