The amount is roughly 56% of all US equities held by households in the US, while the bottom 90% own $4.6 trillion of equities or 12% of the total.
“The wealthiest households have been by far the biggest driver of positive household equity demand,” Goldman Sachs analysts, led by Arjun Menon, said in the report. “Accelerating US economic growth and rising stock prices should continue to support equity purchases by the top 1 per cent.”
https://www.ft.com/content/2501e154-4789-11ea-aeb3-955839e06441