If History Repeats, This Unstoppable ETF Can Make You a Millionaire With a $100,000 Initial Investment and $655 Monthly Contributions Over 20 Years

• Despite the inherent volatility found on Wall Street, the stock market is the world’s greatest wealth-creating machine.

• Today, there are over 4,300 exchange-traded funds (ETFs) for investors to choose from.

• One special ETF, with an ultra-low net expense ratio, attempts to mirror the performance of a popular index that’s averaged an 8.78% annual return over the last 20 years.

• 10 stocks we like better than Vanguard S&P 500 ETF ›

Although there are a lot of ways to make money on Wall Street, none come close to matching the annualized return potential of stocks.

However, this doesn’t mean stocks move from Point A to B in a straight line. Stock market corrections, bear markets, and short-lived crashes are essentially the price of admission to the world’s greatest wealth-creating machine.

For example, the Dow Jones Industrial Average (DJINDICES: ^DJI), S&P 500 (SNPINDEX: ^GSPC), and Nasdaq Composite (NASDAQINDEX: ^IXIC) all endured a short-lived crash during the first week of April in 2025 after President Donald Trump roiled the stock market with the unveiling of his tariff and trade policy. By year’s end, this historic elevator-down move in equities was nearly forgotten, with the Dow, S&P 500, and Nasdaq Composite climbing by 13%, 16%, and 20%, respectively.

When volatility picks up on Wall Street, it’s not uncommon for investors to turn to exchange-traded funds (ETFs). An ETF holds a basket of securities that allows for instant diversification or concentration with just one click. With over 4,300 ETFs for investors to choose from, there’s a good chance one or more ETFs exist that can help you meet your investment goals.

But among this ever-growing pile of ETFs exists an investment vehicle with a flawless track record of generating profits for its long-term investors. If history were to repeat itself, the Vanguard S&P 500 ETF (NYSEMKT: VOO) can be the catalyst that makes you a millionaire.

The Vanguard S&P 500 ETF is one of a few dozen publicly traded ETFs that attempt to mirror the performance of the benchmark S&P 500. Even with the ability for investors to buy fractional shares at some online brokers, purchasing stakes in 500 separate companies would be burdensome.

With one click, the Vanguard S&P 500 ETF gives investors almost identical exposure to the ebbs and flows of Wall Street’s most encompassing stock index.

Two decades ago, on Jan. 14, 2006, the S&P 500 had a closing value of 1,287.61. As of the closing bell on Jan. 14, 2026, the closely watched barometer of Wall Street’s health had climbed to 6,926.60. This roughly 438% cumulative return works out to an 8.78% annualized return rate.

If the assumption is made that history will repeat and this 8.78% annualized return is sustained from Jan. 14, 2026, through Jan. 14, 2046, you’d only need an initial investment of $100,000 and monthly contributions of $655 to top $1 million in 20 years! The investment return table below illustrates how your portfolio can grow significantly over time by mirroring the benchmark S&P 500.

Table by author. Returns do not include dividends or net expense ratios.

There are a couple of things worth noting about the estimated returns above. First, they don’t include the net expense ratio that you’d pay. The net expense ratio covers the annual management and marketing fees that investors pay when putting their money to work in an ETF.

However, the above calculation also doesn’t include the dividends investors would receive. Although the average yield of the S&P 500 has sunk to just 1.13% (as of Jan. 9, per The Wall Street Journal), this yield would more than offset the net expense ratio tied to S&P 500-tracking ETFs. In other words, the table above modestly understates the expected ending balance each year — especially if dividend income were to be reinvested.

More importantly, these eye-popping returns speak to the wealth-creating potential of the S&P 500.

According to an annually updated data set from Crestmont Research, Wall Street’s benchmark index has never had a rolling 20-year period with a negative annualized return. Crestmont examined 107 rolling 20-year periods (1900-1919, 1901-1920, and so on, through 2006-2025) and found that, including dividends, all generated a positive total return.

Although an 8.78% annualized return rate isn’t guaranteed, a positive annualized total return after 20 years is, arguably, the closest thing you’ll get to a guarantee on Wall Street, based on what history tells us.

While there are several S&P 500 index funds for investors to choose from, most gravitate to the Vanguard S&P 500 ETF and the SPDR S&P 500 ETF Trust (NYSEMKT: SPY). The latter was the very first ETF to trade on U.S. exchanges, with its debut occurring almost 33 years ago (Jan. 22, 1993).

In many ways, the Vanguard S&P 500 ETF and SPDR S&P 500 ETF Trust are essentially identical. They both attempt to mirror the performance of Wall Street’s benchmark index and have done a phenomenal job.

But there is one noteworthy difference between the two most popular S&P 500-tracking ETFs that makes the Vanguard S&P 500 ETF the smarter choice: their net expense ratios.

On average, equity index ETFs sport expense ratios of 0.15%. This means $1.50 will go toward fees each year for every $1,000 invested.

The SPDR S&P 500 ETF Trust has a gross net expense ratio of 0.0945%, which is modestly below the average for equity index ETFs. However, the Vanguard S&P 500 ETF has an even lower net expense ratio of just 0.03%.

A difference of 0.0645% doesn’t amount to much if you’re investing a few thousand dollars or only intending to hold your position for a couple of years. However, this nominally minuscule gap in net expense ratio can add up quickly over multiple decades or when dealing with large sums of invested capital. The example provided above, where you initially invest $100,000 and contribute $655 monthly over 20 years, would result in almost $10,000 in additional fees with the SPDR S&P 500 ETF Trust, when compared to the Vanguard S&P 500 ETF.

Although nothing is guaranteed on Wall Street, the Vanguard S&P 500 ETF has history on its side.

Before you buy stock in Vanguard S&P 500 ETF, consider this:

The Motley Fool Stock Advisor analyst team just identified what they believe are the 10 best stocks for investors to buy now… and Vanguard S&P 500 ETF wasn’t one of them. The 10 stocks that made the cut could produce monster returns in the coming years.

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*Stock Advisor returns as of January 19, 2026.

Sean Williams has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Vanguard S&P 500 ETF. The Motley Fool has a disclosure policy.

If History Repeats, This Unstoppable ETF Can Make You a Millionaire With a $100,000 Initial Investment and $655 Monthly Contributions Over 20 Years was originally published by The Motley Fool