The source from the FT has some interesting other numbers:
But the dirty secret behind this myth is that, while access to equities is widespread, ownership is becoming more concentrated. Two decades ago, the wealthiest 10 per cent of Americans held 77 per cent of corporate equities and mutual funds, according to calculations by Lyn Alden, a strategist. The poorest 50 per cent held just 1 per cent, leaving the middle-to-upper cohort with 12 per cent.
Today, however, the wealthiest 10 per cent own 92.5 per cent of the market — a “record high concentration”, Alden notes. And while the richest 1 per cent owned just 40 per cent two decades ago, their share stood at 54 per cent in the most recent data from 2022.