Youth Incorporated Magazine

Carl Icahn, fresh off a victory lap at Netflix NFLX -1.73%, is turning up the burners on his effort at getting Apple AAPL +0.17% to shell out more cash to shareholders.

In a letter to Chief Executive Tim Cook Thursday, Icahn revealed he has increased his stake in the iPhone-maker to 4.7 million shares and called for an immediate tender offer from the company to repurchase $150 billion in stock at $525 per share, funded by some combination of debt and cash on hand.

According to Icahn, the move would immediately increase earnings per share by 33% (by reducing the share count) and send the stock price to $1,250 within three years. He also said he would pledge n0t to tender any of his shares in the buyback.

The billionaire also took a shot at the board’s lack of investment chops.

“In my opinion, any further delay in executing the buyback we hereby propose will reflect this lack of expertise on the board,” he writes. “My firm’s success and my expertise as an investor would be difficult for anyone to argue.”

Even with his increased stake, Icahn controls just half of one percent of Apple’s outstanding shares. But thanks to the septuagenarian’s current winning streak — including cashing in a bit more than half his Netflix stake for a 457% return this month — his voice carries considerable weight.

There is also recent precedent for activist investors nudging Apple toward deploying more capital to shareholders. In February, Greenlight Capital’s David Einhorn, with an even smaller stake than Icahn’s, urged the board to borrow money and issue a new class of preferred stock. While Apple batted down that plan, it did incorporate pieces of it when it issued $17 billion in bonds a few months later to help fund a $100 billion capital return program — buybacks and dividends — through the end of 2015.

That plan satisfied some investors, but not Icahn, who came on board in August with the opinion that not enough of Apple’s prodigious cash flow is being returned to shareholders.

Shares of Apple are down 25% from their September 2012 peak of just over $705. At Thursday morning’s price of $524.59, Icahn’s stake was worth $2.5 billion and in his letter he expressed an intent to add to that position. Since the day before he first unveiled his stake on Twitter in August, Apple shares have risen 12%.

The company, which unveiled updates to its iPad and MacBook line Tuesday, is set to report quarterly earnings after the closing bell Monday, Oct. 28.

Icahn’s letter to Cook was published on Icahn’s new shareholder activism website, shareholderssquaretable.com, which also includes a cartoon that compares the relationship between shareholders and corporate boards and executives to feudalism. The site also includes a quote from Icahn at Texaco’s annual meeting in 1988:

” lot of people died fighting tyranny. The least I can do is vote against it.”

The full letter was published on Icahn’s new shareholder activism website, shareholderssquaretable.com, which also .