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 individual stocks have performed against the broad S&P 500.

Step on up, PNC Financial (NYSE: PNC).                                           

PNC Financial shares have underperformed the S&P 500 over the last quarter-century:

Pncdiv

Source: S&P Capital IQ.

Since 1987, shares have returned an average of 8.2% a year, compared with 9.7% a year for the S&P (both include dividends). That difference adds up fast. One thousand dollars invested in the S&P in 1987 would be worth $19,200 today. In PNC Financial, it'd be worth just $12,300.  

Dividends accounted for a lot of those gains. Compounded since 1987, dividends have made up about 70% of PNC Financial's total returns. For the S&P, dividends account for 39% of total returns.

Now have a look at how PNC Financial earnings compare with S&P 500 earnings:

Pncearn

Source: S&P Capital IQ.

Some outperformance here. Since 1995, PNC Financial earnings per share have increased by an average of 7.2% a year, compared with 6% a year for the broader index.

What's that meant for valuations? PNC Financial has traded for an average of 15 times earnings since 1987 -- below the 24 times earnings of the broader S&P 500.

Through it all, shares have been slight disappointments over the last quarter-century.  

Of course, the important question is whether that will continue. That's where you come in. Our CAPS community currently ranks PNC Financial with a three-star rating (out of five). Care to disagree? Leave your thoughts in the comment section below, or add PNC Financial 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 Motley Fool owns shares of PNC Financial Services. 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.