Name: Embrace Uncertainty, Don't Predict | Ideas Lab | Ep.52
Uploaded: 2026-08-29T17:13:34+00:00
Duration: 2830 s

Speakers

David Booth — Founder, Dimensional Fund Advisors

Kevin Coldiron — Host, Ideas Lab

Summary

David Booth discusses his book Stay Calm and his path from the University of Chicago to founding Dimensional Fund Advisors. He explains why uncertainty is the source of long-run stock market returns and why investors should plan rather than predict. The conversation covers index investing, diversification, small caps, global concentration, tuning out noise, and why he remains optimistic about markets. The overall investment message is to own broad, low-cost, diversified equity portfolios suited to personal circumstances.

David Booth recounts early work at Wells Fargo on the first index portfolio and founding Dimensional in 1981.
He argues uncertainty creates the opportunity for long-run returns, so investors should embrace rather than eliminate it.
The evidence shows professional managers rarely beat the market after fees, making low-cost broad market ownership attractive.
He emphasizes planning around personal liabilities and life changes instead of predicting short-term market moves.
He recommends broad diversification, including small-cap equities and non-US stocks to reduce concentration.
He sees indexing's growth as not a problem for price discovery, with high trading volumes and institutional competition still driving fair prices.
He says lower fees and better risk controls make this a better era for individual investors.

Ideas

David Booth Founder, Dimensional Fund Advisors 0:16

Own low-cost broad market equity index.

Booth argues that professional managers generally cannot beat the market after fees, and that uncertainty is what creates long-run equity returns. He says almost everyone should have some money in public markets, bought inexpensively through a broad market portfolio, because the market rewards participation in human ingenuity and economic competition, with stocks returning about 10% annually through the Depression, World War II, inflation regimes, and COVID.

David Booth Founder, Dimensional Fund Advisors 18:48

Include small-cap equities in diversified portfolio.

Booth explains that Dimensional's original thesis was not simply that small caps would outperform, but that investors should not put all their equity money in large companies. He says investors ought to hold stocks of large companies and small companies, treating small-cap exposure as part of a properly diversified long-term equity allocation.

David Booth Founder, Dimensional Fund Advisors 29:28

Diversify globally beyond concentrated US market.

Booth notes that the US market has become concentrated in the largest stocks, such as the Magnificent Seven. He says a global portfolio of US and non-US equities does not have nearly that concentration, so investors should diversify globally rather than own only US large-cap concentrations.

Embrace Uncertainty, Don't Predict | Ideas Lab | Ep.52

Summary

Ideas

Up Next