This isn't the first time Icahn has called the stock a "no brainer". He said the same thing in a Fast Money Halftime Report" interview Wednesday. As Icahn also promised, his firm followed up today with a letter to Apple shareholders making the case for pressuring the board into increasing its buyback of Apple shares.
"The point is that you don't have to be genius in technology to understand that Apple is selling at a 2014 consensus of 9 times earnings, and amazingly the S&P is selling at 17 times earnings and Apple is really growing," Icahn told CNBC.
(Read more: Icahn: Apple management great; I criticize board)
Apple shares were trading at 556, 0.85% over Wednesday's closing price, and nearly $87 higher than they were when Icahn began buying the stock last year.