Is market concentration justified by megacap earnings share?
Core argument: The young unprofitable company share of total market cap peaked in 2021/2022 during the SPAC boom, served as a leading indicator of the subsequent rout in low-quality stocks, and has since fallen, a positive sign for markets.
Our YUC measure (the young unprofitable company share of total market cap) looks benign. This measure peaked in 2021/2022 with the SPAC boom and was an excellent leading indicator of the rout that was about to happen to low quality stocks. This risk index has fallen since, which is a positive sign for markets. Small cap remains a barren profitability desert (40%+ of small cap companies with negative earnings!) while a falling share of large cap companies have negative earnings. The 10 largest megacap stocks continue to hover at ~35% of market cap, which is an all-time high since 1990. But when looking at the megacap share of total market earnings, they’re more or less keeping pace, particularly when measured based on forward earnings estimates. Tech and TMT valuations are still hovering at the high end of the post-2020 range, ~30x forward earnings expectations. The rest of the market is less aggressively priced, and at 20x forward earnings is priced at the middle of the range since 1990. But these valuations have been creeping up steadily since early 2022.

