The chart below from J. Lyons Fund Management (JLFMI), shows that household and nonprofit’s stock holdings equal 35.7% of their total financial assets as of the end of 2Q 2017. As you can see, this is the second highest level in the history of the data after the 1998-2000 period leading up to the dotcom bubble. You can find the write-up on the chart here discussing the historical implications of this data point and what it could portend for the stock market today. An informative read.