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, Parker Hannifin (NYSE: PH).

Parker Hannifin shares have easily outperformed the S&P 500 over the past quarter-century:

Ph

Source: S&P Capital IQ.

Since 1987, shares have returned an average of 12% 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 Parker Hannifin, it'd be worth $37,500. 

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

Now have a look at how Parker Hannifin earnings compare with S&P 500 earnings:

Ph

Source: S&P Capital IQ.

Decent outperformance. Since 1995, earnings per share have increased by an average of 9.5% per year, compared with 6% annual growth for the broader index.

What's that meant for valuations? Parker Hannifin has traded for an average of 18 times earnings since 1987 -- below the 24 times earnings of the broader S&P 500. Parker Hannifin currently trade for about 10 times next year's earnings.

Through it all, shares have been strong performers over the past quarter-century.  

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