Offer your thoughts or opinion on the input financial query or topic using your financial background.

Explain the details and benefits of rebalancing a retirement portfolio?
Rebalancing a portfolio helps you reduce risk, sell high, and buy low. I'll use international stocks and large cap US stocks.  They both have ups and downs, and they don't always track with each other (international might be up while large cap US stocks are down and vice-versa) If you started with 50% international and 50% large cap stocks and 1 year later you have 75% international and 25% large cap stocks that means that international stocks are doing (relatively) well to large cap stocks.    Comparing only those two categories, large cap stocks are "on sale" relative to international stocks.   Now move so you have 50% in each category and you've realized some of the gains from your international investment (sell high) and added to your large cap stocks (buy low). The reason to rebalance is to lower risk.   You are spreading your investments across multiple categories to manage risk.   If you don't rebalance, you could end up with 95% in one category and 5% in another which means 95% of your portfolio is tied to the performance of a single asset category. I try to rebalance every 12 months and usually get it done by every 18 months.  I like being a hands-off long term investor and this has proven often enough to beat the S&P500.