Earning hundreds of thousands of dollars or more in the stock market may seem like something that's reserved for the ultra-wealthy or elite investors. But it's more attainable than you might think.

You don't need to know a lot about investing to build wealth in the market, but you will need the right investments. Exchange-traded funds (ETFs) are a smart option for many people, as they require much less maintenance than individual stocks yet can still see substantial returns.

While there are many different ETFs to choose from, there are two funds that could potentially turn $100 per week into nearly $800,000 -- with very little effort on your part.

1. Vanguard S&P 500 ETF

The Vanguard S&P 500 ETF (VOO -0.17%) tracks the S&P 500, which means it includes the same stocks as the index itself and aims to mirror its performance over time. The S&P 500 includes stocks from 500 of the largest and most stable companies in the U.S., and by investing in this ETF, you'd own a stake in all of those stocks.

The primary advantage of this ETF is that it's an incredibly safe long-term investment. The S&P 500 itself has not only survived many recessions, bear markets, and crashes over the decades, but it's also earned positive average returns.

If you invest in this ETF, your investment will likely take a hit during periods of volatility. But it's almost guaranteed to recover and go on to see positive returns over time. For those looking for a safe and reliable ETF, you can't go wrong with this one.

Historically, the S&P 500 itself has earned an average annual return of around 10% per year. Because this fund tracks the index, it's likely it will earn similar returns over the long run. If you were investing $100 per week while earning a 10% average annual return, here's approximately how much you could accumulate over time:

Number of Years Total Savings
20 $275,000
25 $472,000
30 $790,000
35 $1,301,000
40 $2,124,000

Data source: Author's calculations via Investor.gov.

Reaching $790,000 in total savings will take approximately 30 years at this rate, but the more time you give your money to grow, the more you'll earn. With an extra decade, you could build a portfolio worth well over $2 million.

One other advantage of this ETF is that it offers a rock-bottom expense ratio of 0.03%. This is one of the lowest among its competitors, which could save you thousands of dollars in fees over time.

2. Vanguard Growth ETF

The Vanguard Growth ETF (VUG -0.08%) is an investment designed to earn above-average returns. It includes 240 stocks from a variety of industries, though about half of the fund is comprised of stocks in the tech sector.

Growth ETFs tend to carry more risk than S&P 500 ETFs, as high-growth companies are often more volatile than their more established counterparts. The tech industry, in particular, is generally hit hard during periods of volatility, so this ETF may see more significant short-term downturns than the previous fund.

That said, this ETF is a strong choice because it balances risk and reward. The top 10 holdings make up roughly half of this fund, and these stocks are behemoth corporations such as Amazon, Apple, Visa, and Home Depot.

The rest of the fund, then, is comprised of up-and-coming stocks with the potential for explosive returns. This approach can limit your risk with the "safe" stocks, while still giving you plenty of room for growth.

Since its inception in 2004, this fund has earned an average rate of return of just under 10% per year. While that may seem low, keep in mind that the tech sector is still struggling amid this downturn, so it's normal to see lower returns in times like these. Over the past 10 years, this ETF has earned an average return of around 13.6% per year.

Even slightly higher-than-average returns can still go a long way. If, for example, you were to invest $100 per week while earning a 12% average annual return, here's roughly how much you'd have over time:

Number of Years Total Savings
20 $346,000
25 $640,000
30 $1,158,000
35 $2,072,000
40 $3,682,000

Source: Author's calculations via Investor.gov.

There are never any promises when investing, so it's unclear exactly what types of returns this fund will earn over decades. This fund is also higher-risk, so be prepared for greater volatility. But because it's designed to earn higher-than-average returns, there's a better chance you'll beat the market with this ETF.

Regardless of where you invest, time is your most valuable resource. The sooner you get started, the easier it will be to generate hundreds of thousands of dollars or more in the stock market.