What: According to S&P Capital IQ data, shares of natural packaged foods maker Hain Celestial Group (HAIN -3.13%) fell more than 10% last month after climbing pretty strongly for most of 2015.

To date, that puts Hain shares up about 4%, having given up most of their spring and early summer gains:

HAIN Chart

HAIN data by YCharts.

So what: Hain shares really started falling in mid-August when the overall market went into one of its biggest sustained sell-offs since the Great Recession. And while the S&P 500 and Dow Jones Industrials indexes have recovered some, shares of Hain have continued to stagnate. Since August 17, shares are off almost 15%, while much of the market has recovered over that time period. 

Now what: This could be a great opportunity to buy shares and to recognize the difference between short-term trader sentiment and the quality and health of the business. The business itself remains strong and is growing quickly, led by founder and CEO Irwin Simon. The company continues to make smart acquisitions in a very fragmented natural and organic packaged foods industry, growing sales and earnings per share at an enormous rate over the past five years:

HAIN EPS Diluted (TTM) Chart

HAIN EPS Diluted (TTM) data by YCharts.

Frankly, the company's share price may have gotten a little ahead of itself, with a price-to-earnings ratio approaching 50 at the 2015 peak. This is well above the historical average. After the recent sell-off, Hain's P/E multiple has fallen to about 36, which is still rich for a packaged foods company, but it's certainly closer to its more recent level. 

Yes, Hain still trades at a premium price, especially to many of its much larger peers, but the reality is that the company is in a superior position to continue to grow, both through acquisitions of key brands as well as organic growth of its already impressive collection of leading brands. With a market capitalization of only $6 billion, Hain Celestial is still a baby in the foods business, but it's operating in one of the fastest-growing segments. 

This short-term market sentiment looks to me like an excellent opportunity to buy and hold for the long term.