As every investor would know, not every swing hits the sweet spot. But really big losses can really drag down an overall portfolio. So consider, for a moment, the misfortune of Medifast, Inc. (NYSE:MED) investors who have held the stock for three years as it declined a whopping 90%. That would certainly shake our confidence in the decision to own the stock. And over the last year the share price fell 74%, so we doubt many shareholders are delighted. We really hope anyone holding through that price crash has a diversified portfolio. Even when you lose money, you don't have to lose the lesson.

So let's have a look and see if the longer term performance of the company has been in line with the underlying business' progress.

View our latest analysis for Medifast

In his essay The Superinvestors of Graham-and-Doddsville Warren Buffett described how share prices do not always rationally reflect the value of a business. By comparing earnings per share (EPS) and share price changes over time, we can get a feel for how investor attitudes to a company have morphed over time.

Medifast saw its EPS decline at a compound rate of 40% per year, over the last three years. The share price decline of 54% is actually steeper than the EPS slippage. So it's likely that the EPS decline has disappointed the market, leaving investors hesitant to buy. The less favorable sentiment is reflected in its current P/E ratio of 6.99.

The graphic below depicts how EPS has changed over time (unveil the exact values by clicking on the image).

Before buying or selling a stock, we always recommend a close examination of historic growth trends, available here.

A Different Perspective

Medifast shareholders are down 74% for the year, but the market itself is up 34%. However, keep in mind that even the best stocks will sometimes underperform the market over a twelve month period. Regrettably, last year's performance caps off a bad run, with the shareholders facing a total loss of 12% per year over five years. Generally speaking long term share price weakness can be a bad sign, though contrarian investors might want to research the stock in hope of a turnaround. While it is well worth considering the different impacts that market conditions can have on the share price, there are other factors that are even more important. Take risks, for example - Medifast has 2 warning signs (and 1 which is a bit unpleasant) we think you should know about.

For those who like to find winning investments this free list of undervalued companies with recent insider purchasing, could be just the ticket.

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

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

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.