The Trillion Ten

These ten mega-cap issues all have market capitalizations of $1 trillion or more and they today account for just under 40% of the value of all US equities.  That percentage continues to grow as they incrteasingly dominate their indices.

According to Morningstar, at the end of 2024, 53% of all US portfolios were passively managed and, of course, they were disproportionately invested in these largest companies. But that's not all:  current academic research now suggests that the "passive AUM" is much larger than we previously estimated.  Perhaps as much as 70%-80% of all stocks outstanding. (Chinco and Sammon:  The Passive Ownership Share is Double What You Think it Is, Journal of Financial Economics, 2024).

The inordinate size of this overhang requies close monitoring and the articulation of an active, defensive potfolio strategy.