"Just Keep Buying" Review: Data Proves the Key to Wealth Isn''t "When to Buy" but "Keep Buying"

Table of Contents

Why I Wanted to Read This Book

Just Keep Buying—this concept was actually something I kept repeating when I started working as a financial advisor seven years ago. The wealth in the stock market is just sitting there, waiting for us to claim it. Do you need to buy and sell, buy low and sell high? Of course—but the frequency of buying comes from “consistency,” and the frequency of selling comes from “need.” If I already understand the concept, do I still need to read books like this? Don’t forget—the purpose of reading is to enrich yourself. As long as even one sentence in a book can level you up, any type of book is absolutely worth reading.

What Is Just Keep Buying About?

The author of this book is Nick Maggiulli, a data scientist and investment expert. In the book, he describes watching his grandfather gamble away his retirement money on horse racing, leading to a miserable old age. Growing up, Nick used his strengths in data analysis and investment expertise to debunk common investment myths. Backed by data, he proposes the simplest yet most effective investment mindset: “Just Keep Buying.” The book’s core message encourages readers to start investing as early as possible and develop the habit of investing consistently, regardless of market direction—Just Keep Buying. The author believes that time is an investor’s most important asset, because time can’t be bought with money, and everyone’s time is limited. So rather than spending time trying to predict market timing, it’s better to seize the time and enter the market early, letting compound interest grow your assets over time.

The Book Presents 3 Arguments for Why You Should “Just Keep Buying”

• Dollar-cost averaging beats buying the dip: Based on historical data analysis, the author found that long-term regular investing typically outperforms the buy-the-dip approach. No one can accurately predict market bottoms, and waiting for the perfect moment actually means missing out on market gains.
• Investing in broad-market ETFs beats picking individual stocks: The author argues that investors should choose market-cap-weighted ETFs rather than individual stocks. Individual stocks carry higher risk, require more research time, and most actively managed fund managers underperform the market anyway.
• Focus on your career and increase your income: The author advises investors to focus on boosting their primary income, as this is the most stable and reliable way to increase investment capital. The book also emphasizes the importance of saving, encouraging readers to build good savings habits so they have more money to invest. Just Keep Buying offers an investment approach that’s perfect for people who want to start investing but don’t know where to begin. The investment philosophy is simply “Increase your income, just keep buying”—focus on your career and keep investing, and you can build wealth.

Should the Poor Focus on Saving While the Rich Invest Aggressively?

Defining “Poor” and “Rich”

First, we need to clarify: how do we define “poor” and “rich”? By income, assets, or some other measure? Different definitions may lead to different investment strategy recommendations. Personally, I suggest using the most straightforward definition.

For someone earning NT$30K, NT$40K, NT$50K, or NT$80K per month, investing 30% of their salary with an assumed 8% return—what would the returns look like after 5, 10, 15, and 20 years? How big is the difference? Here’s a comparison table:

The point of this table isn’t to emphasize the rich-poor divide, but to show that when our salary is lower, we should actively invest in ourselves to increase our income. For example, someone earning NT$30K could save up NT$100K, take courses at a tech training institute (like Taiwan’s Institute for Information Industry), transition into software engineering, and significantly boost their earning potential.

The Relationship Between “Saving” and “Investing”

“Saving” is the first step in building wealth—without savings, there’s no capital to invest. The book mentions the concept of “paying yourself first,” which encourages people to set aside a portion of their income first as investment capital upon receiving their paycheck. This is what I always call “Earn > Save > Spend.” Once you’ve saved 3 to 6 months of emergency funds, you should start actively investing through dollar-cost averaging, consistently putting money into the market.

“Investing” is the way to grow your capital. By investing in stocks, bonds, funds, and other instruments, you can earn higher returns than bank deposits, fight inflation, and if the market exceeds expectations, you may reach your financial goals even faster.

“Time” Is More Important Than “Money”

The book repeatedly emphasizes the importance of “time,” because time can’t be bought with money, and everyone’s time is limited.

For young people, especially during the period of fastest income growth (ages 25–35), you should focus on improving your skills and increasing your income, because this is the most efficient way to build wealth.

Whether “poor” or “rich,” everyone should seize the time and start investing early so that through the power of compound interest, wealth can grow steadily.

The Importance of “Money”

• Invest in yourself to improve your quality, and increase the quantity of your money.
• The accumulation of money influences compound interest outcomes.
• Blindly chasing returns may overexpose your money to risk.

The Importance of “Time”

• Time is a key factor affecting investment returns.
• The compound effect of time can grow wealth steadily.
• The value of time can’t be measured in money—once it’s gone, it’s gone forever.

No Matter Who You Are, Start Investing Early

Regardless of your income level, once you’ve saved 3–6 months of emergency funds, you should Just Keep Buying. Only through Just Keep Buying can you harness the power of compound interest over time and grow your wealth steadily.

Further Reading

Lazy Da’s Conclusion

懶大

金融科技新創 CEO | 獨立財務顧問

After reading Just Keep Buying, you’ll have the ability to distinguish between assets and junk.
The core philosophy of “Just Keep Buying”
Invest early: Due to the compound effect of time, the earlier you start investing, the faster your wealth grows.
Invest regularly: Through dollar-cost averaging, you can spread investment risk and build a disciplined investing habit.
Invest for the long term: Investing is a long-term process—don’t let short-term market fluctuations affect your decisions.

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