The richest 1% of Americans own 31% of the nation’s wealth. And the richest one-tenth of Americans own more than two-thirds of the nation's wealth, according to Fed data through the end of March. Total wealth in the U.S. is here divided into four groups: The wealthiest 1%; the next 99% to 90%; the middle 50-90%; and the bottom half. The wealthiest benefit disproportionately from stock market gains.