Does Diversification Add Risk or Reduce It?

In this final episode of our four-part series, Paul Merriman compares three powerful approaches for a lifetime of investing:

• 100% S&P 500: high-risk, high-reward growth.

• 60/40 mix of S&P 500 and bonds: a defensive balance.

• 100% U.S. Four-Fund strategy: large-cap blend, small-cap blend, large-cap value, small-cap value.

Paul uses 55 years of data (1970–2024) to show how these portfolios performed during both accumulation and retirement distributions. Paul highlights the following critical tables from the Bootcamp series. 

Table B1 - Fine Tuning Table: S&P 500 Equity Portfolio 

Table B4 - Fine Tuning Table: US 4-Fund Equity Portfolio
Table C4 - Fixed Contributions ($1,000/yr): US 4-Fund Equity Portfolio
Table D4.4 - Fixed Distributions (Conservative-$40,000/yr): US 4-Fund Equity Portfolio  
Table H2 – Sound Investing Portfolios (100% Equity)
Table H2A – Sound Investing Portfolios (60/40)
Table D1.4 – Fixed Distributions ($40k + inflation)

Did diversification deliver higher returns without extra risk? Or was the classic S&P 500 enough?

Get the numbers, the tables, and the takeaways to help you decide.