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, Hewlett-Packard (NYSE: HPQ).

Hewlett-Packard shares have actually underperformed the S&P 500 over the last three decades, with most of the gap occurring in the last two years:

Source: S&P Capital IQ.

Since 1980, shares have returned an average of 10.4% 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 Hewlett-Packard, it'd be worth $23,000. 

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

Now have a look at how Hewlett-Packard earnings compare with S&P 500 earnings:

Source: S&P Capital IQ.

There's some outperformance here. Since 1995, earnings per share have grown by an average of 6.3% a year, compared with 6% annual growth for the broader index.

What's that meant for valuations? Not much. Hewlett-Packard has traded for an average of 23 times earnings since 1980 -- not too different than the 21 times earnings of the S&P 500. It's far different today, however. HP shares currently trade at around five times forward earnings.

Through it all, shares have been disappointing performers 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 Hewlett-Packard with a three-star rating (out of five). Do you disagree? Leave your thoughts in the comment section below, or add Hewlett-Packard to My Watchlist.