Markets rarely move in straight lines, and 2025 was a powerful reminder of the value in diversification. As we reflect on the year behind us and look ahead to 2026, several themes stand out.

This comprehensive study looks at stock market turbulence and how it can affect investment performance.

Professor Seyhun studied stock market returns and risk for all months and all days for the 99 years from 1926 through 2024, inclusive. His findings highlight the challenge of market timing, since a small number of months or days accounted for a large percentage of market gains and losses.