First, Icahn says he's bought an additional $500 million in Apple stock, bringing his total to $3 billion. Which, it's worth noting, is still less than 1% of the company's market cap that was hovering just south of $500 billion on Wednesday.
But he also made clear he's not backing down from his campaign to get Apple to boost its stock buyback program.
"We feel $APPL board is doing great disservice to shareholders by not having markedly increased its buyback," Icahn tweeted. "In-depth letter to follow soon."
Icahn also couldn't help but note that Apple's stock was trading at $468 per share on Aug. 13 when he first revealed his investment. In mid-day trading on Wednesday, Apple's stock hit $552.02.
He said buying more stock in the company was a "no brainer."
Icahn had previously filed a shareholder proposal calling on Apple to increase its buyback program. The proposal is not binding on the company and will be voted on by shareholders at the company's annual meeting on Feb. 28.
Meanwhile, here's Icahn's latest tweets: