This Warren Buffett Advice Could Help You Build a $1 Million Portfolio -- Even if You Know Nothing About Picking Stocks

Warren Buffett is considered one of the most successful investors of our time. And much of his success has been rooted in identifying strong businesses and investing in them accordingly.

But let's face it -- if all of us had the same stock-picking ability as Buffett, we'd be millionaires. And while there are definitely steps you can take to become a more educated investor and get better at picking stocks, that may just not be in your wheelhouse. And that's okay.

In fact, Buffett himself says that you don't need to be a wiz at picking stocks to build a lot of wealth over time. All you need to do is stick to one simple strategy.

Put your money into the broad market

The stock market's average annual return over the past 50 years has been 10%. Now when we talk about stock market returns, we're generally referring to returns generated by the S&P 500 index, which consists of the 500 largest publicly traded stocks.

What this means is that if you consistently invest in S&P 500 stocks over time, there's a good chance your portfolio will enjoy a similar return. And there's a very easy way to invest in the S&P 500 without having to actually go out and buy shares of 500 different stocks -- load up on S&P 500 index funds instead.

Index funds are passively managed funds that aim to invest in and match the performance of different market benchmarks. So an S&P 500 index fund will have the goal of performing comparably to the S&P 500 itself.

The nice thing about index funds is that they're passively managed. You're not paying for a fund manager to actively choose investments and devise a strategy, like you are when you buy mutual funds. Because of this, the fees associated with index funds tend to be very low. And you want to keep your fees low so they don't eat into your returns.

Meanwhile, Buffett recommends S&P 500 index funds for the typical investor. He was even quoted as saying, "Consistently buy an S&P 500 low-cost index fund. Keep buying it through thick and thin."

To be clear, Buffett doesn't necessarily follow this advice himself. But he doesn't have to, because he knows how to pick stocks. But for the average investor with limited knowledge, S&P 500 index funds are a solid choice.

Could S&P 500 index funds be your ticket to a $1 million portfolio?

We just learned that you might end up with a 10% average annual return if you load up on S&P 500 index funds. So, let's say you invest $200 a month in those funds over 40 years and end up with that return. You'll also end up with a portfolio worth over $1 million. Make it $500 a month, and you'll be looking at over $2.6 million.

But to be clear, Buffett's advice isn't to just buy S&P 500 index fund shares and hold them for a few years. Rather, the key is to hold them over a long period of time. If you're willing to do that, you may be surprised at how much wealth you're able to grow -- even if you feel you know nothing about picking stocks.