Some stocks are best avoided. It hits us in the gut when we see fellow investors suffer a loss. Spare a thought for those who held HF Foods Group Inc. (NASDAQ:HFFG) for five whole years - as the share price tanked 83%. And some of the more recent buyers are probably worried, too, with the stock falling 40% in the last year. The last week also saw the share price slip down another 10%. 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.

Since HF Foods Group has shed US$20m from its value in the past 7 days, let's see if the longer term decline has been driven by the business' economics.

View our latest analysis for HF Foods Group

Because HF Foods Group made a loss in the last twelve months, we think the market is probably more focussed on revenue and revenue growth, at least for now. Generally speaking, companies without profits are expected to grow revenue every year, and at a good clip. That's because it's hard to be confident a company will be sustainable if revenue growth is negligible, and it never makes a profit.

In the last half decade, HF Foods Group saw its revenue increase by 23% per year. That's well above most other pre-profit companies. So it's not at all clear to us why the share price sunk 13% throughout that time. It could be that the stock was over-hyped before. While there might be an opportunity here, you'd want to take a close look at the balance sheet strength.

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

Take a more thorough look at HF Foods Group's financial health with this free report on its balance sheet.

While the broader market gained around 27% in the last year, HF Foods Group shareholders lost 40%. 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 13% 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. It's always interesting to track share price performance over the longer term. But to understand HF Foods Group better, we need to consider many other factors. For instance, we've identified 1 warning sign for HF Foods Group that you should be aware of.