OCMR Investment Perspectives Volume 2.2

Revisiting the Principles of Risk and Risk Management in the Context of Modern Portfolio Theory

Asset Allocation Alone May Not Be Enough: The Growing Idiosyncratic Risk in Today’s S&P 500 Index

Traditional asset allocation has long served as the main way investors manage risk. They spread money across stocks, bonds, and other assets and count on historical correlations to provide diversification. Yet in today's highly concentrated market, this approach by itself is often not enough.

Modern Portfolio Theory tells us that broad diversification reduces unsystematic (idiosyncratic) risk - the company-specific problems such as regulatory actions, valuation drops, or product setbacks. What remains is systematic risk that affects the whole market. For many years the cap-weighted S&P 500 did this job well. That is no longer the case.

The Concentration Problem

As of mid-2026 the top 10 stocks make up roughly 36-41% of the S&P 500 (according to S&P Dow Jones Indices, Slickcharts, and MacroMicro data as of May/June 2026), close to levels last seen near the dot-com bubble. Passive fund inflows keep pushing this higher. As the biggest companies rise, index funds automatically buy more of them.

Investors who think they own a diversified portfolio of 500 companies are heavily exposed to the performance of just a few names. Company-specific risks from the largest tech and AI leaders now drive a big part of the index's movements.

Implicit vs. Explicit Risk Management

Implicit risk management depends on built-in portfolio management structures such as traditional asset allocation, assumed historical correlations, and passive cap-weighted indexing. It is simple and inexpensive, but it works less effectively when markets become this concentrated.

Explicit risk management uses targeted tools to address specific risks directly. These methods require more effort or cost, but they add the precision that implicit approaches now lack.

Cap-Weighted vs. Equal-Weighted S&P 500

Data sources for the table (as of mid-2026): Top 10 concentration and sector weights come from S&P Dow Jones Indices reports, Slickcharts, MacroMicro, RBC Wealth Management, and T. Rowe Price analyses. Sector comparisons draw from S&P Dow Jones Indices, Invesco, and Investopedia. Valuation discounts for the equal-weighted index rely on FactSet data reported by Invesco and Raymond James. The style differences are well-established traits noted across multiple independent studies.

Equal-weighted indexing offers a straightforward way to improve diversification inside your equity holdings.

Explicit Risk Management Tools: Key ETF Classes

Investors can add targeted protection on top of traditional asset allocation with these ETF categories:

• Buffered / Defined Outcome ETFs: Provide a set downside buffer, such as protection against the first 10–20% of losses, paired with an upside cap for a specific period.
• Hedged Equity ETFs: Combine stock holdings with dynamic or rolling options overlays like puts or collars to limit drawdowns while keeping some upside.
• Tail-Risk Hedging ETFs: Use out-of-the-money puts or similar strategies built to gain during sharp market drops.
• Volatility-Focused ETFs: Track volatility products that usually rise when stock prices fall, helpful for short-term protection.
• Trend-Following / Managed Futures ETFs: Adjust exposure across different assets based on price trends and can help during extended equity declines.

These ETF types let you apply explicit risk management without having to trade options on your own.

Practical Takeaways

1. Check your actual exposure and see how much depends on the top 10 holdings.
2. Mix cap-weighted holdings with equal-weighted or multi-factor approaches for better natural diversification.
3. Add a 5–20% allocation to buffered, hedged equity, or tail-risk ETFs depending on your comfort with risk.
4. Rebalance on a regular basis between different weighting methods and hedging tools.

Bottom Line: Asset allocation still matters, but extreme concentration in the major indexes means it cannot stand alone anymore. Effective risk management today combines strong implicit diversification with clear, targeted explicit tools.

Diversification still offers real value. It simply needs more deliberate effort than just buying the broad market and expecting old patterns to continue.

DISCLOSURES

This material is for informational and educational purposes only and does not constitute investment advice, a recommendation, or an offer to buy or sell any security. The views expressed are general in nature and are not tailored to any specific investor’s financial situation, objectives, or risk tolerance. Buffered ETFs involve risks, including loss of principal, and may not provide the intended buffer or cap outcomes if shares are bought or sold prior to the end of the outcome period. Outcomes are dependent on market conditions and the timing of investment relative to the ETF’s reset date. Any references to models, analytics, or probability assessments are based on assumptions and estimates that may not prove to be accurate. There is no guarantee that any model or analysis will achieve its intended results. Data is believed to be reliable but is not guaranteed as to accuracy or completeness. BufferLABS is a DBA of Ogard Capital Market Research LLC is an SEC registered investment advisor. Past performance is not indicative of future results.