Investing isn't easy. Even Warren Buffett counsels that most investors should invest in a low-cost index like the S&P 500. That way, "you'll be buying into a wonderful industry, which in effect is all of American industry," he says.

But there are, of course, companies whose long-term fortunes differ substantially from the index. In this series, we look at how members of the S&P 500 have performed compared with the index itself.

Step on up, Wells Fargo (NYSE: WFC).

Wells Fargo shares have crushed the S&P 500 over the last three decades:

Source: S&P Capital IQ.

Since 1980, shares returned an average of 15.6% a year, compared with 11.1% a year for the S&P (both include dividends). That difference adds up fast. One thousand dollars invested in the S&P in 1980 would be worth $29,400 today. In Wells Fargo, it'd be worth $103,600.

Dividends accounted for a lot of those gains. Compounded since 1980, dividends have made up about two-thirds Wells Fargo's total returns. For the S&P, dividends account for 41.5% of total returns.

Now have a look at how Wells Fargo earnings compared with S&P 500 earnings:

Source: S&P Capital IQ.

Again, pretty good outperformance. Since 1995, Wells Fargo's earnings per share have grown by an average of 9.3% a year, compared with 6% a year for the broader index. Wells has truly proven its worth as one of the few megabanks capable of consistently adding value.

What's it all meant for valuations? Not much. Wells Fargo has traded for an average of 15 times earnings since 1980 -- below the 21 times earnings for the broader S&P 500.

Through it all, Wells Fargo shares have clearly been outperformers over the last three decades.

Of course, the important question is whether that will continue. That's where you come in. Our CAPS community currently ranks Wells Fargo with a four-star rating (out of five). Do you disagree? Leave your thoughts in the comment section below, or add Wells Fargo to My Watchlist.

Fool contributor Morgan Housel doesn't own shares in any of the companies mentioned in this article. Follow him on Twitter @TMFHousel. The Fool owns shares of and has created a covered strangle position in Wells Fargo. Motley Fool newsletter services have recommended buying shares of Wells Fargo. The Motley Fool has a disclosure policy. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. Try any of our Foolish newsletter services free for 30 days.