It's not possible to invest over long periods without making some bad investments. But really big losses can really drag down an overall portfolio. So spare a thought for the long term shareholders of Perion Network Ltd. (NASDAQ:PERI); the share price is down a whopping 71% in the last three years. That would be a disturbing experience. The more recent news is of little comfort, with the share price down 70% in a year.

Now let's have a look at the company's fundamentals, and see if the long term shareholder return has matched the performance of the underlying business.

See our latest analysis for Perion Network

To quote Buffett, 'Ships will sail around the world but the Flat Earth Society will flourish. There will continue to be wide discrepancies between price and value in the marketplace...' 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.

Although the share price is down over three years, Perion Network actually managed to grow EPS by 31% per year in that time. Given the share price reaction, one might suspect that EPS is not a good guide to the business performance during the period (perhaps due to a one-off loss or gain). Alternatively, growth expectations may have been unreasonable in the past.

Since the change in EPS doesn't seem to correlate with the change in share price, it's worth taking a look at other metrics.

We note that, in three years, revenue has actually grown at a 19% annual rate, so that doesn't seem to be a reason to sell shares. It's probably worth investigating Perion Network further; while we may be missing something on this analysis, there might also be an opportunity.

You can see below how earnings and revenue have changed over time (discover the exact values by clicking on the image).

We know that Perion Network has improved its bottom line over the last three years, but what does the future have in store? It might be well worthwhile taking a look at our free report on how its financial position has changed over time.

A Different Perspective

While the broader market gained around 34% in the last year, Perion Network shareholders lost 70%. However, keep in mind that even the best stocks will sometimes underperform the market over a twelve month period. On the bright side, long term shareholders have made money, with a gain of 10% per year over half a decade. If the fundamental data continues to indicate long term sustainable growth, the current sell-off could be an opportunity worth considering. I find it very interesting to look at share price over the long term as a proxy for business performance. But to truly gain insight, we need to consider other information, too. Case in point: We've spotted 1 warning sign for Perion Network you should be aware of.