Nvidia is a stock that's been synonymous with generating high-powered returns in recent years. The chipmaker is a big player in the artificial intelligence market, as its chips are the go-to option for many tech companies building out their chatbots and other next-gen products. But Nvidia also isn't a cheap investment -- its market cap is around $3 trillion. Trying to earn a high return with a stock that's already one of the most valuable companies in the world won't be easy, especially with expectations being so high for the business at this point.

If you want to earn a big return and turn $25,000 into more than $1 million, there is a safer and better way to do so -- assuming that you're willing to be patient. An exchange-traded fund (ETF) can allow you to generate some massive gains over the years, while also allowing you to keep your risk fairly low. You won't be overly exposed to just a single stock, the way you would be if you only bought shares of Nvidia.

An ETF that can be ideal for growth investors is the Invesco QQQ Trust (QQQ -1.33%). Here's why it can be a no-brainer buy.

The Invesco fund gives investors broad diversification in many growth stocks

If you want exposure to the top growth stocks in the world, odds are you'll look to the Nasdaq exchange, where many top tech stocks trade. The Invesco fund will narrow the list even further, however, giving you exposure to just the top 100 non-financial stocks on the exchange. This means you'll avoid some of the riskier stocks on the Nasdaq. Instead, you'll get access to some of the best and brightest growth stocks in the world.

Nvidia is one of the top holdings in the ETF, but it only accounts for 8% of its total weight. The ETF also holds shares of Costco Wholesale, Alphabet, Amazon, and many other big-name stocks. Although it's heavily skewed toward tech stocks (they account for half of the fund), other sectors of the market are represented in the fund as well, including healthcare, industrials, and consumer discretionary stocks. Collectively, these stocks can help you generate strong and steady returns over the years.

How the ETF can help grow your portfolio to $1 million

For a $25,000 investment to turn into $1 million or more, it will need to grow to 40 times its original value. To accumulate that kind of return, you'll want to focus on the long term, such as a period of 25 to 30 years. That way, you aren't setting your expectations too high or focusing on risky small-cap stocks that may appear to have a lot of upside.

Over a period of 25 years, you would need to average a compounded annual growth rate (CAGR) of approximately 15.9% for an investment to grow to 40x its original value. But if you're able to remain invested for 30 years, the necessary CAGR falls to 13.1%.

Historically, the Invesco ETF has been a strong investment to hang on to. When including dividends, its total returns over the past decade have totaled 417%, which equates to a CAGR of 17.9%. That doesn't, of course, mean that it will generate those types of returns over the next couple of decades, but it's indicative of the strength of the growth stocks it possesses in its portfolio, and their ability to generate massive returns. Even at a slower growth rate, the fund has the potential to make you a millionaire with a $25,000 investment, as long as you're willing to be patient and hang on for the long haul.

The Invesco QQQ Trust makes for a great option for any investor

Whether you track growth stocks or just want a diversified portfolio, the QQQ fund can be a great investment to add to your own holdings. It has a fairly low expense ratio of 0.2%, and with exposure to top growth stocks, it's a no-brainer investment that can be suitable for just about any type of investor. It can also be a great default investment to put money into, especially if you don't want to have to track individual stocks.