Bellevue-based Coinstar Inc., owner of the popular Redbox DVD kiosks surged in the stock market Thursday, amid speculation that the company may be bought out.

The company experienced a growth of more than 7.5 percent, more than doubling its overall growth during the year, now at more than 14 percent. The stock finished at $51.88.

The rise came as reports that the company has been talking with a private equity firm about a purchase, according to the New York Post.

Officials from Coinstar were not immediately available, but CEO Paul Davis told analysts he was unaware of any possible transaction.

“We have no idea where it came from,” Che said in remarks to analysts at a Canaccord Genuity Global Growth conference in Boston. “We’re head-down focused on running the business and we’re happy with the progress we’re making but that’s about all we’ll comment.”

Redbox, which is positioning itself as a primary competitor to Netflix in the latest evolution of movie consumption, makes up the majority of Coinstar’s income. The rest comes from the counting machines often found in grocery stores.