As an investor, mistakes are inevitable. But really big losses can really drag down an overall portfolio. So consider, for a moment, the misfortune of Varta AG (ETR:VAR1) investors who have held the stock for three years as it declined a whopping 88%. That would certainly shake our confidence in the decision to own the stock. And over the last year the share price fell 41%, so we doubt many shareholders are delighted. Furthermore, it's down 27% in about a quarter. That's not much fun for holders. While a drop like that is definitely a body blow, money isn't as important as health and happiness.

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.

Check out our latest analysis for Varta

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...' 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.

Varta saw its share price decline over the three years in which its EPS also dropped, falling to a loss. Since the company has fallen to a loss making position, it's hard to compare the change in EPS with the share price change. However, we can say we'd expect to see a falling share price in this scenario.

The image below shows how EPS has tracked over time (if you click on the image you can see greater detail).

We're pleased to report that the CEO is remunerated more modestly than most CEOs at similarly capitalized companies. But while CEO remuneration is always worth checking, the really important question is whether the company can grow earnings going forward. Dive deeper into the earnings by checking this interactive graph of Varta's earnings, revenue and cash flow.

A Different Perspective

While the broader market gained around 9.2% in the last year, Varta shareholders lost 41%. However, keep in mind that even the best stocks will sometimes underperform the market over a twelve month period. Unfortunately, last year's performance may indicate unresolved challenges, given that it was worse than the annualised loss of 10% over the last half decade. We realise that Baron Rothschild has said investors should "buy when there is blood on the streets", but we caution that investors should first be sure they are buying a high quality business. 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. To that end, you should be aware of the 2 warning signs we've spotted with Varta .