Bio-fuel crop developer Ceres Inc., which saw a huge jump in its share price earlier this month, fell sharply Monday, losing 17.8 percent of its value.

The company’s stock has been active in recent weeks, jumping after an analyst wrote that he expected key positive commercialization announcements in July. But the shares have eroded in the last few days.

Shares of the company, which produces genetically modified seeds used in biofuel production, closed at $1.97 on June 10. Pavel Molchanov, an analyst at Raymond James & Associates, wrote June 11 that he expected positive reports on the company’s crops in Brazil next month, and that would mark a key commercialization milestone for the firm. Within days, the share price more than doubled, reaching $4.26 on June 13.

But since then, shares have declined 40 percent off the June 13 close.

In July, the company is expected to announce strong yields for sweet sorghum crops now being tested in Brazil. A severe drought in the country last year weakened Ceres’ position, but weather has been better this year, and in a conference call to discuss second quarter earnings, company officials hinted that results should be better for this year’s crops.

Shares of Ceres closed down Monday 55 cents, or 17.8 percent, to close at $2.54 on the Nasdaq.