LAKEWOOD, Colo. — Shares of Natural Grocers by Vitamin Cottage were up more than 20% in their first days of trading last week after the organic-product retailer had its stock priced at $15 per share and opened at $18.

“We thought this was a good time to come to market — an opportune moment,” Kemper Isely, chief executive officer of the historically secretive company, told CNBC on the morning of the initial public offering.

His comment was in response to a question about riding on the coattails of two industry companies it will compete with in some ways — Whole Foods Market and The Fresh Market — both relatively high-growth operators that have seen their stock prices soar amid the economic malaise.

Natural Grocers operates a small box like The Fresh Market, with a strong focus on organic foods that appeals to purists, somewhat akin to Whole Foods, but perhaps with more semblance to mom-and-pop health-food stores.

More Natural Grocers news: Natural Grocers Sets Expansion Plans

Like its bigger, publicly traded rivals, Natural Grocers also has aggressive expansion plans. Isely told CNBC his 55-store chain is eyeing a 20% compound annual growth rate for new stores in the next five years — including 12 in the next year and between 84 and 100 new stores over a five-year span. The company previously said it believes the U.S. market can support 1,100 of its 12,000-square-foot stores.

Company executives were not available for comment to SN last week.

In filings with the Securities and Exchange Commission, Natural Grocers said it recorded 40 consecutive quarters of comparable-store sales gains, including gains of 10% through the first half of its current fiscal year.