Athenahealth Inc. Chief Executive Officer Jonathan Bush said the company’s shares are set to rise as the provider of Internet-based services for physician practices grabs more market share.

“This is a great time to get into the stock,” said Bush in an interview on CNBC. “I am absolutely sure that Athenahealth is a $1,000-a-share stock,” he said, adding that he didn’t know when it would hit that price.

Bush dismissed hedge fund manager David Einhorn’s comments earlier this week that the company’s stock was too high, saying he didn’t know how Einhorn developed his evaluation. Einhorn, co-founder of Greenlight Capital Inc., said May 5 that Athenahealth shares could decline as much as 80 percent because the stock “is simply at the wrong price.”

Athenahealth fell 2.8 percent to $104.82 at 8:37 a.m. New York time. The shares of the Watertown, Massachusetts-based company slumped 14 percent the day after Einhorn made his comments.