Concentration… in Red Underline
Concentration, a positive attribute as one reads a newsletter.
In a mean-reverting capital market, concentration may instill a less sanguine emotion.
Question…?
The answer begins on July 3rd, 1884. A significant heat wave was impacting New York City, with the temperature reaching a scorching 96°F. The weather was described as "cruel."
Charles Dow, legend has it without breaking a sweat, sat down to fearlessly write his Afternoon Letter, the very genesis of modern bellwether indices.
“We present today an average of the prices of active stocks. The purpose of this average is to show, from day to day, the general movement of the market, making no allowance for the relative value or importance of the stocks which compose it. The average is obtained by adding together the last prices of the stocks included and dividing the sum by the number of stocks”
Charles describes what we now know as a price-weighted index. Today, most well-known indices lean towards market-capitalization weighting, a comparable formula which replaces the price of a single share with the total market value of all shares. In less words, the more sizable the company, the more sizable the influence and capital allocation.
Why does this matter?
With the evolution of exchanges and technology facilitated trading, a seemingly endless number of financial products emerged, each of which allocate capital to these financial constructs. Naturally, investors are common to benchmark performance to the bellwether Standard & Poor's 500 index.
This is where the question of concentration becomes less academic and more consequential.
Today’s market-cap weighted indices are not merely reflections of the market, they are increasingly defined by a narrow and at times, entirely discretionary selection of companies. A select few names drive a disproportionate share of performance, capital flows, and investor sentiment.
In momentum-driven environments, this concentration can feel like confirmation. Strength begets strength. Winners keep winning.
In a mean-reverting regime, concentration can quietly transform from a tailwind into a source of fragility.
When leadership narrows:
Diversification declines, despite appearances
Passive capital becomes self-reinforcing
Reversals, when they occur, alarm market-danger
Dear investors,
This is not a call to abandon indices or passive investment philosophy. More so, this is an invitation to understand what you own beneath the surface.
Because when you allocate your monies to bellwether indices, you’re not only buying the market.
You’re buying its leadership.
And increasingly, it is concentration.
Love,
Corey
