Hello! Welcome to the final lesson in our module on long-term investing.
In the past few lessons, we've assembled some powerful building blocks. You've learned:
- What ETFs and index funds are.
- How to evaluate them using key metrics like expense ratios.
- How to invest consistently using Dollar-Cost Averaging (DCA).
Today, we're putting it all together. We will use those building blocks to construct a complete, diversified portfolio. The learning outcome for this lesson is to build a simple, diversified portfolio using a small number of broad-market index funds or ETFs.
We will focus on a widely respected and beautifully simple strategy known as the Three-Fund Portfolio. This approach was popularized by followers of John Bogle, the founder of Vanguard, and it aligns perfectly with your interests in both the practical "how-to" of investing and the philosophy behind sound financial strategy.
What is a Three-Fund Portfolio?
Instead of trying to pick individual winning stocks (a notoriously difficult game), the Three-Fund Portfolio strategy proposes that you buy the entire market. You do this by holding just three types of low-cost, broad-market index funds or ETFs:
- A Total US Stock Market Fund: Gives you ownership in thousands of US companies, from giants like Apple and Amazon to smaller, growing firms.
- A Total International Stock Market Fund: Gives you ownership in thousands of companies outside the US, across both developed (e.g., Germany, Japan) and emerging (e.g., China, Brazil) markets.
- A Total US Bond Market Fund: A collection of thousands of high-quality government and corporate bonds, which act as a stabilizer for your portfolio.
To get a concise overview of this concept and why it's so powerful, please watch this first video.
The 3-Fund Portfolio Blueprint—Investing Made Simple
The video 'The 3-Fund Portfolio Blueprint' by Tae Kim from the Financial Tortoise channel provides an excellent introduction to the core components of this strategy.
Please watch from the beginning until 02:33. The video will clearly define the three funds that make up this simple but comprehensive portfolio.
By combining these three funds, you achieve instant global diversification across tens of thousands of stocks and bonds.
The Power of Simplicity: Why Does It Work?
Your interest in economics and philosophy will find a home here. The reason this simple strategy is so effective lies in a few core principles. It's not just about what you own; it's about avoiding common mistakes.
The key advantages include:
- Global Diversification: You're not betting on any single company, sector, or country.
- Low Cost: The funds used have rock-bottom expense ratios, meaning more of your money stays invested and compounds for you.
- Simplicity & Discipline: It removes the temptation to constantly trade or chase hot stocks, which is where many investors go wrong.
- Proven Performance: By definition, you capture the return of the entire market. Over the long run, this has consistently outperformed the majority of professional, actively managed funds.
This next video explains these benefits in detail.
The 3 Fund Portfolio - Simple Investing for Beginners
In 'The 3 Fund Portfolio' by Humphrey Yang, he clearly articulates the major benefits of this strategy, from its low costs to its ability to protect you from your own biases.
Watch from 01:51 to 05:39. Pay close attention to how low fees impact your long-term returns and why simply tracking the market is a winning strategy for most people.
How to Build Your Three-Fund Portfolio: A Practical Guide
This is the "how-to" part. Building your portfolio involves two main decisions: choosing your allocation and choosing your funds.
Step 1: Choose Your Asset Allocation
Asset allocation is simply the percentage of your portfolio you will dedicate to each of the three funds. This is the single most important decision you'll make, as it determines your portfolio's overall risk and potential return.
You need to decide two things:
-
Your Stock vs. Bond Split: This depends heavily on your age and risk tolerance. Since you have a very long time horizon, you can afford to be more aggressive and hold a higher percentage in stocks, which have higher long-term growth potential. As you get closer to needing the money, you would gradually increase your bond allocation for more stability. A common rule of thumb for young investors is a 90% stock / 10% bond split.
-
Your US vs. International Stock Split: Within your stock allocation, you need to decide how to split it between US and international funds. The US currently makes up about 60% of the global stock market's value. A "market-weight" allocation would be 60% US / 40% International. Many US investors have a "home country bias" and prefer a split like 70/30 or 80/20. There's no single right answer, but a 60/40 to 80/20 range is a very reasonable starting point.
To make this concrete, let's look at a helpful guide.
The article 'Three-Fund Portfolio' from hellonectarine.com provides an excellent table with example asset allocations based on age, which can serve as a great starting point.
Please read the section titled 'How much of each do I buy?' and carefully examine the table under 'Ok, so how much at which age?'. Find the row corresponding to your approximate age to see a sample allocation.
For example, using that table, a 25-year-old investor would have an allocation of:
- 54% US Stocks
- 36% International Stocks
- 10% Bonds
This corresponds to a 90% stock / 10% bond split, with the stocks divided 60/40 between US and International (54% is 60% of 90%).
Here is a visual example of what an allocation might look like.
Step 2: Choose Your Funds
Once you have your target percentages, you just need to buy the corresponding funds. The great news is that the major low-cost brokerages all offer excellent, nearly identical options. Because you are using ETFs, you can buy them at any brokerage, usually with no trading fees.
The table below, compiled from the provided resources, gives you the specific ETF ticker symbols you would use at any major brokerage.
| Asset Class | Vanguard ETF | iShares (BlackRock) ETF | Schwab ETF |
|---|---|---|---|
| Total US Stock Market | VTI | ITOT | SCHB |
| Total Intl. Stock Market | VXUS | IXUS | SCHF |
| Total US Bond Market | BND | AGG | SCHZ |
How to use this table: If you have an account at Fidelity, Schwab, or any other broker and want to build a three-fund portfolio using Vanguard ETFs (a very popular choice), you would simply buy VTI, VXUS, and BND in your desired proportions.
For more details and options, including mutual fund equivalents, the Bogleheads Wiki is the definitive source.
The 'Three-fund portfolio' article on the Bogleheads Wiki is the canonical reference for this strategy. It provides exhaustive lists of funds for various providers.
Skim the sections 'Vanguard funds' and 'Other than Vanguard, Boglehead-style'. You don't need to memorize them, but notice how each brokerage (Vanguard, Fidelity, Schwab) has its own equivalent mutual funds and ETFs for implementing the same core strategy.
Tying It All Together: A Case Study
Let's see how this works in practice, connecting it back to the Dollar-Cost Averaging strategy from our last lesson.
The case study of 'Tiffany' in the hellonectarine.com article is a perfect practical summary of how to implement and maintain this portfolio over time.
Please read the final section, 'Putting it all together: A case study'. Notice how Tiffany determines her allocation, makes her purchases, and uses auto-contributions (DCA) to stay on track.
As you can see, the process is:
- Decide on your asset allocation.
- Calculate the dollar amount for each fund based on your initial investment.
- Execute the trades to buy the three ETFs.
- Automate future contributions (your DCA plan) to buy more of each fund in the same proportions.
- Revisit your allocation every few years or as your life circumstances change.
Test your understanding!
Let's say you are 30 years old and have $10,000 to start your investment portfolio. Using the age-based table from the Nectarine article, answer the following:
- What is your target asset allocation (percentages for US Stocks, International Stocks, and Bonds)?
- If you choose to use Vanguard ETFs, what are the three ticker symbols you would buy?
- How much money would you invest in each of the three ETFs to establish your portfolio?
Show answer
-
Asset Allocation: According to the table, a 30-year-old would have a target allocation of 54% US Stocks, 36% International Stocks, and 10% Bonds.
-
Ticker Symbols: The Vanguard ETFs for these asset classes are VTI (US Stocks), VXUS (International Stocks), and BND (Bonds).
-
Investment Amounts:
- VTI (US Stocks): 54% of $10,000 = $5,400
- VXUS (Int'l Stocks): 36% of $10,000 = $3,600
- BND (Bonds): 10% of $10,000 = $1,000
Conclusion
Congratulations on completing this module! You have now progressed from understanding basic concepts to designing a complete, sophisticated, and effective long-term investment portfolio. This three-fund strategy is a powerful tool used by millions of investors to build wealth patiently and reliably.
Key Takeaways:
- A Three-Fund Portfolio consists of a US stock index fund, an international stock index fund, and a bond index fund.
- It provides maximum diversification at a very low cost and helps you stay disciplined.
- Building one is a two-step process: choose your asset allocation (stocks vs. bonds, US vs. international) and then select the corresponding low-cost ETFs or index funds.
- This strategy combines perfectly with Dollar-Cost Averaging for consistent, automated investing over the long term.
A Look Ahead:
We've answered the questions of what to buy (broad-market index funds) and how to buy it (DCA). The next logical question is where to hold these investments. In our next module, "Tax-Advantaged Investing," we will explore the crucial differences between a standard taxable brokerage account and powerful retirement accounts like IRAs and 401(k)s. This concept, known as "asset location," can have a massive impact on your wealth over time.