Chipotle Mexican Grill's shares tumbled by as much as 9.2 percent Thursday after the company announced its strategy to revitalize the fast-casual restaurant chain but provided few details on its future growth prospects.

"The call was lighter on detail than we would have liked so we expect weakness in the stock today," Peter Saleh, an analyst at BTIG, wrote in a research note Thursday. Shares plunged to an intraday low of $415.06 but recovered some ground in afternoon trading to close at $428.36, down 6.3 percent.

The company announced plans Wednesday to spend up to $135 million to win back customers and reposition Chipotle as a lifestyle brand. The expenses will cover a new ad campaign, digital investments to speed mobile and online orders as well as the costs of closing up to 65 underperforming locations.

While CEO Brian Niccol told investors he can "easily see a future where Chipotle more than doubles revenue to over $10 billion," he was scant on how that will play out in the coming quarters.

"[The] conference call disappointed in that it lacked meaningful near-term catalysts or fine tuned financial objectives," Matthew DiFrisco, an analyst at Guggenheim, wrote in a research note Wednesday.

Chipotle executives declined to update or reaffirm earnings guidance set in previous quarters. The only hint about second-quarter results came from Niccol who said positive sales trends seen in the first quarter had carried over. Executives also said the company will book up to $60 million of its restructuring charges during the second quarter.

"We are watching sales and transactions every day and we look at it by region and by day part. And what we continue to see is good performance in all the day parts," Niccol said, adding that he was optimistic that would continue to improve.

Saleh said he believes "management is firmly on the right path" to win back customers who lost confidence Chipotle after a series of food safety problems plagued the company beginning in 2015.