Every three years (supposedly), the IRS publishes a study of personal wealth statistics based on a mashup of estate tax returns and individual tax returns.
It's pretty interesting stuff for small business folks because what it shows is small business ownership is a route to financial independence.
The study samples about 600,000 of the wealthiest individuals in country. This represents about the top quarter percent. The first bracket in the top quarter percent (of about 100,000 individuals) shows a mean net worth of roughly $3,057,895.
About 30% of these folks hold closely held corporate stock with a mean value of $930,352.45
About 45% of these folks hold an interest in an unincorporated business with mean value of $912,146.31
About 16% of these folks hold an interest in a farm with mean value of $2,477,547.41
One can download the Excel spreadsheet with the data here:
https://www.irs.gov/statistics/soi-tax-stats-all-top-wealthholders-by-size-of-net-worthP.S. The rest of these people's net worth is basically a house, often some real estate, some cash, and then a little of retirement savings.