Billionaire investor Carl Icahn told CNBC that bitcoin "seems like a bubble."

Though Icahn stressed that he "just doesn't get" the mania surrounding the novel cryptocurrency, he did compare the dramatic appreciation of bitcoin to a famous land bubble in the 18th century.

"It's sort of amazing to me," Icahn said Thursday on "Halftime Report." "If you read history books about all these bubbles, like in Mississippi — where John Law went around selling all this land in Mississippi that was sort of worthless and the French were going crazy giving him all this money. And then one night it all blew up ... to me, this is what this is."

One of the major grievances leveled at bitcoin has been regular swings in value, a trend unbecoming of a global means of monetary exchange. Bitcoin's more than 1,000 percent appreciation over the past year has also drawn bubble concerns.