When you buy shares in a company, there is always a risk that the price drops to zero. But when you pick a company that is really flourishing, you can make more than 100%. For example, the Ampco-Pittsburgh Corporation (NYSE:AP) share price had more than doubled in just one year - up 118%. Better yet, the share price has gained 178% in the last quarter. And shareholders have also done well over the long term, with an increase of 82% in the last three years.

Since it's been a strong week for Ampco-Pittsburgh shareholders, let's have a look at trend of the longer term fundamentals.

To paraphrase Benjamin Graham: Over the short term the market is a voting machine, but over the long term it's a weighing machine. 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.

During the last year Ampco-Pittsburgh saw its earnings per share (EPS) drop below zero. While some may see this as temporary, we're a skeptical bunch, and so we're a little surprised to see the share price go up. We might get a clue to explain the share price move by looking to other metrics.

Revenue was pretty stable on last year, so deeper research might be needed to explain the share price rise.

The image below shows how earnings and revenue have tracked over time (if you click on the image you can see greater detail).

It's probably worth noting we've seen significant insider buying in the last quarter, which we consider a positive. That said, we think earnings and revenue growth trends are even more important factors to consider.

A Different Perspective

It's good to see that Ampco-Pittsburgh has rewarded shareholders with a total shareholder return of 118% in the last twelve months. Notably the five-year annualised TSR loss of 3% per year compares very unfavourably with the recent share price performance. This makes us a little wary, but the business might have turned around its fortunes. 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. Consider for instance, the ever-present spectre of investment risk. We've identified 3 warning signs with Ampco-Pittsburgh (at least 2 which are potentially serious) , and understanding them should be part of your investment process.

There are plenty of other companies that have insiders buying up shares. You probably do not want to miss this free list of undervalued small cap companies that insiders are buying.

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

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.