ASU Professor's Research Shows US Stock Returns Highly Concentrated Among Few Winners, About 4% of Stocks Contribute to All Market Net Gains
Research by Arizona State University professor Bessembinder shows that since 1926, long-term net wealth in the US stock market has primarily been created by a very small number of stocks.
About 4% of stocks contribute to all market net gains, with 86 stocks generating half of the wealth in the US stock market, approximately $16 trillion.
Buying pressure is essentially concentrated on a few super winners, while selling pressure comes from the majority of stocks that have long underperformed risk-free returns; this indicates that diversifying to hold the "whole market" does not equate to diversifying returns.
Source: Public Information
ABAB AI Insight
The most important conclusion of this research is not that "most stocks are poor performers," but that "the positive returns in capital markets are extremely reliant on a few blockbuster companies." This means that the stock market is not a machine that evenly distributes wealth, but rather a filtering system that presents a majority of failed samples alongside a few extreme winners.
In terms of capital pathways, long-term wealth is not generated evenly across all companies, but rather concentrated in bursts from new technologies, new business models, and winner-takes-all network effects. Over the past century, companies that have contributed significant wealth are typically not stable enterprises, but those that have gained platform, standard, channel, or scale advantages at a certain stage.
Comparable historical cases include the internet, semiconductors, cloud computing, and AI: the more platformized and stronger the network effects in an industry, the more wealth will concentrate among a few leading companies. What you see is the index rising, but the real returns are paid by a few giants that can withstand cycles.
This fundamentally belongs to capital concentration: the market appears dispersed, but actual returns are increasingly concentrated among a few names; the reason this occurs is that technological diffusion and economies of scale continuously amplify the marginal advantages of winners, while most companies can only provide "market presence" and struggle to deliver "market net value addition."
ABAB News · Cognitive Laws
The market is dispersed, but returns are concentrated.
Most stocks explain the world, while a few stocks create wealth.
Researching the entire market is less effective than first identifying that 4%.