Research Library
Our guides make recommendations like "favor low-cost index funds" or "avoid trying to time the market." This section shows the actual evidence behind those recommendations — summarized in plain English, with sources, methodology, and honest limitations, not just headline conclusions.
Studies covered
Most actively managed funds have underperformed their benchmark index over long periods — here's the actual data.
DALBAR The Investor Behavior GapThe average investor has historically earned less than the funds they invest in, due to mistimed buying and selling.
Vanguard Research Dollar-Cost Averaging vs. Lump-Sum InvestingWhen you have a lump sum to invest, does spreading it out actually help? Here's what the historical data shows.
Morningstar Why Investors Miss Out on Fund ReturnsInvestors have captured roughly 15% less than their funds' own total returns — and volatility predicts the gap better than fees do.
How we use research on this site
We summarize third-party, publicly available research from established sources — we don't run our own studies. Every research summary states what the study actually measured, its methodology, its limitations, and clearly separates the evidence from our own interpretation of what it means practically. Figures come from the cited publisher and may be updated in later editions of the underlying study, so we link to the original source on every page.
Educational only — not financial advice.