In 2023, Wall Street analyst Michael Hartnett from Bank of America assigned a nickname to a group of seven of America's largest technology stocks -- not just for their size, but also their ability to consistently beat the S&P 500 (^GSPC -0.84%) index.

He called this group the "Magnificent Seven," and they have delivered a median return of 886% over the last 10 years, compared to a return of 185% for the S&P:

NVDA data by YCharts

In other words, investors who haven't owned the Magnificent Seven stocks over the last decade have probably underperformed the broader market by a very wide margin. But here's the good news: The Vanguard Mega Cap Growth ETF (MGK -0.80%) offers investors a simple way to buy them all, with a splash of diversification.

It's an exchange-traded fund (ETF) that invests exclusively in America's largest companies, and the Magnificent Seven account for over half of the total value of its entire portfolio. Here's how the ETF could turn an investment of $200,000 into $1 million over the next 15 years (or less).

Image source: Getty Images.

The Magnificent Seven represent half of the value of this ETF

The Vanguard Mega Cap Growth ETF tracks the CRSP U.S. Mega Cap Growth Index, which invests in the top 70% of the cumulative market capitalization of the CRSP U.S. Total Market Index. The CRSP U.S. Total Market Index holds each of the 3,537 stocks listed on American exchanges.

The U.S. Mega Cap Growth Index (and by extension, the Vanguard ETF) only holds 69 stocks, which highlights the incredible concentration of wealth in corporate America. To put it another way, just 69 companies represent 70% of the entire value of the 3,537 companies listed on American stock exchanges.

It isn't entirely surprising considering the Magnificent Seven stocks have a combined market capitalization of $17 trillion, which they have accumulated by dominating various subsegments of the technology industry including cloud computing, semiconductors, e-commerce, social media, and electric vehicles.

As a result, the Magnificent Seven stocks alone represent 56.3% of the total value of the Vanguard ETF's portfolio of 69 stocks:

Data source: Vanguard. Portfolio weightings are accurate as of May 31, 2025, and are subject to change.

Each of the Magnificent Seven companies are now focused on artificial intelligence (AI), which could be their largest financial opportunity ever. Microsoft, Amazon, and Alphabet have created their own AI models and chatbots, but they also operate some of the world's best data centers, which they rent to other AI developers for profit. Even the smallest Magnificent Seven company, Tesla, is now a leading developer of AI-powered autonomous driving software.

But it's Nvidia that has become the poster child for the AI revolution thanks to its graphics processing units (GPUs) for the data center, which are the most powerful chips for developing AI models.

As I mentioned earlier, the Vanguard Mega Cap Growth ETF gives investors an opportunity to own the Magnificent Seven stocks in a more diversified manner than buying them outright. Within its top 20 holdings, investors will find several popular non-technology stocks like Visa, Eli Lilly, Costco Wholesale, McDonald's, and Intuit.

Turning $200,000 into $1 million in under 15 years

The Vanguard Mega Cap Growth ETF has delivered a compound annual return of 13% since it was established in 2007, beating the S&P 500 which has generated an average annual gain of 10.1% over the same period.

A 13% annual return would be enough to turn an investment of $200,000 into $1 million within around 13 years and three months. In fact, the ETF could still deliver a fivefold return within 15 years even if its annual return slowed to 11.3%.

However, returns appear to be accelerating instead. The ETF has delivered an annual gain of 16.1% over the last 10 years, a 17.8% annual gain over the last five years, and a 20.7% annual gain over the last three years. The surging dominance of the Magnificent Seven stocks and their peers across the tech and tech-adjacent industries are the main drivers of those increased returns.

I'm not suggesting they will remain at those elevated levels over the long run, but AI could certainly help the Vanguard ETF maintain its above-average performances for the next few years at least. Global consulting firm PwC predicts AI will add $15.7 trillion to the global economy by 2030, and a lot of that value will be driven by the tech giants in this ETF.

Nevertheless, it's never a good idea to put all of your eggs in one basket. This Vanguard ETF is a great buy primarily for investors with a diversified portfolio that has little or no exposure to the Magnificent Seven stocks already.