Investing a large lump sum today into a diversified exchange-traded fund (ETF) and simply holding on to it can be a great way to grow your portfolio over the long term. Historically, stocks have risen in value, and the S&P 500 has averaged an annual return of around 10% per year.

But can investing $50,000 today into a top fund like the Vanguard Growth Index Fund ETF (VUG 1.39%) be enough to grow your portfolio to $1 million by the time you retire? Let’s take a look at how probable that is.

A top-performing ETF that’s focused on growth

ETFs can provide you with lots of diversification, and while there are many types you can hold, I’m going to focus on one in particular, which may be ideal for long-term investors: the Vanguard Growth Index Fund ETF.

This ETF provides exposure to the top growth stocks in the country. There were 166 stocks in the fund as of the end of March, including Apple, Meta Platforms, Tesla, and many other big names.

For long-term investors, this is a good example of the type of ETF you may want to hang on to for the long haul, since it will likely rise in value and has a good chance of outperforming the market given its focus on growth stocks.

VUG data by YCharts.

While the ETF has outperformed the S&P 500 in recent years, it’s not guaranteed to continue to do so. But it’s nonetheless a good ETF to hang on to in your portfolio if you’re planning to remain invested for not only years but also decades. Growth stocks can be volatile from one year to the next, but over the long haul, they can produce significant returns for investors.

Here’s how much a $50,000 investment might grow over the years

If you invest in the Vanguard Growth Index Fund, you may be able to outperform the market’s long-run gains. But for the sake of being conservative, in the table below, I’ve shown how a $50,000 investment might grow if you underperform the market, match its long-run average, and if you slightly beat it.

Calculations and table by author.

As you can see, even if you underperform the market, over a 35-year period, your portfolio may still grow to be worth more than $1 million. If you’re retiring in 30 years, however, then unless you outperform the market, you may not reach that value. The average growth rate can play a significant role in your long-run gains, and unfortunately, it’s hard to predict what that will be.

There are no guarantees when it comes to investing

The above table shows a range of possibilities, but ultimately there is no definitive way to know whether $50,000 can be enough to get to $1 million by the time you retire. A longer time horizon may increase the chances, but there’s still the risk that the year that you want to pull money out of stocks, the market may crash.

There is always going to be some risk, but you’re still better off hanging on for the long haul and holding a diverse portfolio of investments since that can give you a good balance of safety along with long-term growth potential.