Here's the case for keeping investing simple that I find most persuasive after 12 years of reading about personal finance.

Every additional complexity in your investment strategy has two costs: the time to learn and implement it, and the behavioral risk of abandoning it when the complexity becomes inconvenient.

A three-fund portfolio (VTI + VXUS + BND) has no behavioral friction. There are no decisions beyond your contribution amount and periodic rebalancing. It doesn't require reading financial news, evaluating companies, or predicting macro trends.

Every layer of complexity added — sector tilts, factor investing, individual stocks, options — adds decisions that require ongoing attention and introduce opportunities for behavioral mistakes.

The research consistently shows that return benefits of sophisticated strategies are erased by higher fees, taxes, and behavioral errors that come with complexity. The simpler strategy that you'll execute correctly for 30 years will outperform the sophisticated strategy you'll execute inconsistently.