Key Facts
• New NISA investment system launched in 2023.
• Bestseller Just Keep Buying sold over 400,000 copies globally.
• Study compared two investment strategies over 40 years (1920–1980):
– Dollar-Cost Averaging (DCA): $100 invested monthly.
– Buy-the-Dip: $100 saved monthly, invested only during market dips.
• Results: DCA outperformed Buy-the-Dip in over 70% of cases.
• Simulations showed Buy-the-Dip failed 97% of the time when timing was off by two months.
• Immediate lump-sum investing outperformed dollar-cost averaging in 76% of cases (1997–2020).
• Lump-sum investing averaged 4% higher annual returns than dollar-cost averaging.
• Key insight: Most markets rise over time, making early and frequent investing critical.
• Book emphasizes 21 proven financial rules based on over 100 years of data.
• Author Nick Maggiulli is a data scientist and COO at Ritholtz Wealth Management.
Summary
The book Just Keep Buying by Nick Maggiulli highlights the superiority of dollar-cost averaging (DCA) and lump-sum investing over strategies like Buy-the-Dip. Using over a century of data, the author demonstrates that waiting for market lows is ineffective, as markets generally rise over time. Simulations reveal that DCA outperformed Buy-the-Dip in 70% of cases over 40 years, and lump-sum investing surpassed dollar-cost averaging in 76% of cases between 1997 and 2020. The book advocates for early and consistent investing, supported by 21 actionable financial rules. Maggiulli’s data-driven approach challenges conventional financial wisdom, offering readers practical strategies to build wealth.
