A young adult with the median income can build a sizable portfolio that pays a substantial dividend by following this simple investment strategy.The median annual income for full-time workers ages 25 to 34 was approximately $60,000 as of September 2025. That would be about$45,500 after federal and state income taxes even in the worst scenario. Financial advisors recommend saving 20% of after-tax income for retirement, which means $9,100 per year ($758 per month) for the median worker in that age group.Howe ...