Understanding Stock Market Mechanics and Index Fund Benefits

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Correction history

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1. 28 July 2026 · corrected by Emir Baycan

   Corrected an arithmetic error and four overstated claims: fixed the fee-impact table so that a $100,000 portfolio at 7% gross over 30 years grows to about $751,000 at 0.05% fees (6.95% net), $574,000 at 1.0% (6.0% net), and $498,000 at 1.5% (5.5% net), replacing the incorrect $622,000 and $558,000 figures; softened the Efficient Market Hypothesis claim that beating the market is impossible to 'extremely difficult and rare, hard to distinguish from luck' since markets are not perfectly efficient; qualified 'every 20-year real return was positive' as a feature of the relatively successful U.S. market history and not a future guarantee; qualified the SPIVA active-fund underperformance rate as varying by period, category, and market rather than one fixed 85-90%; and softened the Barber-Odean investor-behavior finding to an average-in-sample result rather than a universal causal rule.

   Before

   The article's fee table gave $100,000-at-7% 30-year values of about $753,000, $622,000, and $558,000; said EMH makes outperformance impossible; said every historical 20-year real return was positive; gave one fixed SPIVA underperformance rate; and framed Barber-Odean, DALBAR, and Carhart as universal causal rules.

   After

   Recomputed the fee table at the stated net returns, qualified the EMH and 20-year-return claims, scoped the SPIVA figure, and framed the investor-behavior studies as sample findings rather than universal laws.

   Why: The fee figures were an arithmetic error and the other claims were more absolute than the evidence supports. Corrections recompute the table and scope the claims rather than adding new sources.

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Full contribution timeline

1. Correction 28 July 2026

   Emir Baycan: Corrected an arithmetic error and four overstated claims: fixed the fee-impact table so that a $100,000 portfolio at 7% gross over 30 years grows to about $751,000 at 0.05% fees (6.95% net), $574,000 at 1.0% (6.0% net), and $498,000 at 1.5% (5.5% net), replacing the incorrect $622,000 and $558,000 figures; softened the Efficient Market Hypothesis claim that beating the market is impossible to 'extremely difficult and rare, hard to distinguish from luck' since markets are not perfectly efficient; qualified 'every 20-year real return was positive' as a feature of the relatively successful U.S. market history and not a future guarantee; qualified the SPIVA active-fund underperformance rate as varying by period, category, and market rather than one fixed 85-90%; and softened the Barber-Odean investor-behavior finding to an average-in-sample result rather than a universal causal rule.

   Proof record →