For many, the main point of investing in the stock market is to achieve spectacular returns. And we've seen some truly amazing gains over the years. To wit, the Rambus Inc. (NASDAQ:RMBS) share price has soared 395% over five years. If that doesn't get you thinking about long term investing, we don't know what will. And in the last week the share price has popped 10.0%.

Since the stock has added US$576m to its market cap in the past week alone, let's see if underlying performance has been driving long-term returns.

To paraphrase Benjamin Graham: Over the short term the market is a voting machine, but over the long term it's a weighing machine. One imperfect but simple way to consider how the market perception of a company has shifted is to compare the change in the earnings per share (EPS) with the share price movement.

During the five years of share price growth, Rambus moved from a loss to profitability. That kind of transition can be an inflection point that justifies a strong share price gain, just as we have seen here.

You can see how EPS has changed over time in the image below (click on the chart to see the exact values).

We know that Rambus has improved its bottom line over the last three years, but what does the future have in store? Take a more thorough look at Rambus' financial health with this free report on its balance sheet.

A Different Perspective

While the broader market gained around 23% in the last year, Rambus shareholders lost 8.1%. However, keep in mind that even the best stocks will sometimes underperform the market over a twelve month period. Longer term investors wouldn't be so upset, since they would have made 38%, each year, over five years. It could be that the recent sell-off is an opportunity, so it may be worth checking the fundamental data for signs of a long term growth trend. It's always interesting to track share price performance over the longer term. But to understand Rambus better, we need to consider many other factors. For instance, we've identified 3 warning signs for Rambus (2 are a bit unpleasant) that you should be aware of.

If you like to buy stocks alongside management, then you might just love this free list of companies. (Hint: many of them are unnoticed AND have attractive valuation).

Please note, the market returns quoted in this article reflect the market weighted average returns of stocks that currently trade on American exchanges.

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This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.

Have feedback on this article? Concerned about the content? Get in touch with us directly. Alternatively, email editorial-team@simplywallst.com