Beyond Mega Caps: Barron’s 400 and the Importance of Diversification in U.S. Equities

For much of the past decade, U.S. equity returns have been increasingly concentrated in a relatively small group of large cap growth companies. More recently, however, market leadership has begun to broaden, prompting many investors to reassess portfolios heavily dependent on a handful of mega cap stocks. As a result, interest has grown in strategies that provide exposure to a wider set of companies, sectors, and sources of return.

One way to achieve that diversification is through investment approaches that emphasize company fundamentals rather than market capitalization. The Barron’s 400 Index is built from a universe of U.S. companies selected using MarketGrader’s proprietary fundamental research methodology, which identifies companies with strong growth, value, profitability, and cash flow characteristics. The index is available in both equally weighted and market-cap-weighted versions, each reflecting the same underlying company selection discipline but differing in how constituents are weighted. The Barron’s 400 ETF (BFOR), managed by SS&C ALPS Advisors, seeks to track the equally weighted version of the index.[1] Unlike traditional large, mid, or small cap indexes, the Barron’s 400 is not constrained by market capitalization. Its constituents span the full spectrum of the U.S. equity market and currently include companies such as NVIDIA, Apple, Alphabet, Microsoft, Broadcom, Eli Lilly, Micron Technology, AMD, Visa, and Johnson & Johnson, among many other widely held large caps.

Yet despite owning several of the market’s largest companies, BFOR is classified by Morningstar as a Mid Cap Blend strategy rather than a large cap fund. At first glance, that may seem counterintuitive. However, Morningstar’s classification framework is based on the aggregate characteristics of a portfolio, including the market cap profile and value or growth orientation of its holdings, rather than the presence or absence of any individual stock. As a result, a portfolio can own a number of large cap companies while still exhibiting the overall characteristics of a Mid Cap Blend strategy.

Understanding why BFOR is classified this way helps explain one of its most distinctive characteristics. While many investors own U.S. equities through market cap-weighted benchmarks, those portfolios increasingly derive a significant portion of their returns from a relatively small group of mega cap companies. The question for investors seeking broader diversification is not simply which companies BFOR owns, but how the portfolio behaves. Does it behave like a large cap growth strategy? A traditional mid cap fund? Or does it provide exposure to a different mix of return drivers altogether?

Earlier this year, we discussed the rotation taking shape within U.S. equities and how it was beginning to affect the equally weighted and market cap-weighted versions of the Barron’s 400 differently. That discussion focused on changes in market leadership and investor preferences. The analysis below approaches the same topic from a different perspective by examining how the Barron’s 400 ETF (BFOR), which tracks the equally weighted version of the index, has historically behaved and where its returns have come from.

To answer that question, MarketGrader recently conducted a returns-based attribution analysis of BFOR using Russell’s six-factor model (see below for a brief primer on what this is). While the analysis does not determine Morningstar’s classification, it provides an independent lens through which to examine the portfolio’s historical behavior and the sources of its returns. The results help explain why Morningstar classifies BFOR as a Mid Cap Blend fund and illustrate how an equally weighted, fundamentally selected portfolio can behave quite differently from traditional market cap-weighted benchmarks.

BFOR’s Sources of Returns

Returns-based attribution attempts to identify the combination of size and style factors that best explains a portfolio’s historical returns. By comparing those factor exposures with realized performance, investors can gain insight into whether returns were driven primarily by broad market characteristics or by the underlying companies held in the portfolio.

A factor loading can be thought of as an implied exposure. For example, a portfolio with a high loading to Mid Cap Value behaves similarly to portfolios with value-oriented mid cap stocks. By examining these exposures, investors can determine whether returns were primarily driven by broad factor exposures or by the underlying companies held in the portfolio.

Figure 1: Three-Year Factor Loadings for the Barron’s 400 ETF (BFOR) and Two US Mid Cap Benchmarks (Period Ended May 31, 2026)

The three-year analysis confirms Morningstar’s classification of BFOR as a Mid Cap Blend strategy. Approximately 76% of the portfolio’s return profile can be explained by exposure to mid cap value and growth factors, while roughly 23% is associated with small cap value exposure. Notably, the analysis found virtually no exposure to either large cap growth or small cap growth factors.

That distinction is important. While many investors today remain heavily exposed to large cap growth through broad market indexes and concentrated technology allocations, BFOR’s return profile has historically been driven by a very different set of companies.

More importantly, the factor analysis explains only part of the fund’s returns. Over the three years ended May 31, 2026, BFOR generated an annualized return of 21.1%. Of that, approximately 18.7% can be explained by traditional size and style factors. The remaining 2.38 percentage points, or 238 basis points per year, can be attributed to stock selection.

Among the ETFs included in our analysis, the iShares Russell Mid-Cap ETF (IWR) and Vanguard Mid-Cap ETF (VO) exhibited factor profiles most similar to BFOR. Despite these similarities, BFOR generated a substantially larger stock-selection contribution than either fund, suggesting that company selection played an important role in the portfolio’s overall results.

Five-Year Analysis Tell a Similar Story

Figure 2: Five-Year Factor Loadings for the Barron’s 400 ETF (BFOR) and Two US Mid Cap Benchmarks (Period Ended May 31, 2026)

The five-year results reinforce the conclusions from the shorter time frame. Factor exposures remained remarkably consistent, with mid cap value, mid cap growth, and small cap value accounting for virtually the entire return profile of the Barron’s 400 ETF.

Over the five years ended May 31, 2026, BFOR generated a 10.0% annualized return. The factor model explained approximately 7.8% of that return, leaving 215 basis points per year attributable to stock selection.

This persistence is noteworthy. While factor exposures explain how the portfolio behaves, they explain only part of the realized outcome. Across both the three- and five-year periods, the analysis suggests that company selection contributed meaningfully to performance.

Figure 3: Annualized Return Attributable to Stock Selection for BFOR and Select U.S. Mid Cap ETFs

Among the ETFs included in the analysis, BFOR generated one of the strongest and most persistent stock-selection contributions, as shown in Figure 3. In fact, its five-year stock selection effect was approximately double that of the next best ETF in the peer group and substantially higher than either the Russell Midcap Index or the S&P MidCap 400 Index.

Long-Term Results Relative to Peers

If the attribution analysis helps explain how BFOR generated its returns, Morningstar’s peer-group rankings provide a useful measure of how those returns compare with competing mid cap strategies. This is illustrated in Figure 4.

Figure 4: BFOR’s Annualized Returns and Corresponding Morningstar Rankings Against Actively Managed Mid Cap Blend Peers

While BFOR’s one-year ranking was near the middle of its category, its longer-term results place it firmly within the top quartile of peers over three, five, and ten years.

Conclusion

As investors reassess concentrated large-cap growth exposure and seek broader diversification, understanding the sources of return across different equity strategies becomes increasingly important.

Our analysis suggests that BFOR has historically behaved as a fundamentally selected, mid cap-oriented diversifier rather than as a proxy for large cap growth exposure. While its return profile reflects meaningful exposure to mid cap value and growth factors, a substantial portion of its long-term performance cannot be explained by those factors alone. Across both the three- and five-year periods, company selection appears to have been an important contributor to results.

These findings also highlight an important distinction between the equally weighted and market cap-weighted versions of the Barron’s 400. While the equal-weighted methodology has historically produced a return profile that resembles a Mid Cap Blend strategy, the market cap-weighted version behaves differently and reflects a greater influence from the market’s largest companies. In a forthcoming article, we will examine the market cap-weighted Barron’s 400 in greater detail and explore how its long-term performance compares with traditional large cap U.S. benchmarks.

Note:

What is Russell’s Six-Factor Model?

Russell’s six-factor model is a returns-based attribution framework designed to explain how a portfolio behaves relative to six common equity factors: Large Cap Value, Large Cap Growth, Mid Cap Value, Mid Cap Growth, Small Cap Value, and Small Cap Growth.

Rather than examining a portfolio’s holdings directly, the model analyzes its historical returns and estimates the combination of factor exposures that best explains those returns. The resulting factor loadings can be interpreted as the portfolio’s implied exposures to each size and style segment of the market.

For example, a portfolio with a 50% loading to Mid Cap Value and a 25% loading to Mid Cap Growth has historically behaved much like a portfolio with those characteristics. Any return that cannot be explained by these factor exposures is typically attributed to stock selection.

One useful application of the model is determining whether a portfolio’s returns are primarily driven by large cap growth exposure or by a broader mix of size, style, and stock-selection effects.

[1] MarketGrader developed the Barron’s 400 Index in collaboration with Dow Jones and Barron’s and serves as the index’s administrator. The Barron’s 400 ETF (BFOR) is managed and distributed by SS&C ALPS Advisors. MarketGrader does not sponsor, manage, market, or promote the ETF and does not provide investment advice regarding the fund or any other investment product.

References to BFOR in this article are provided solely to illustrate how the Barron’s 400 methodology has been expressed in a real-world investment vehicle and to analyze the historical characteristics and sources of return associated with the index. All performance data cited are sourced from Morningstar Direct unless otherwise noted.