Tech billionaire Michael Dell mocks old foe Carl Icahn about his holding company's plunging stock price

• Tech billionaire Michael Dell jabbed at his old rival Carl Icahn this week.
• Dell mocked Icahn Enterprises' plunging stock price in a post on X.

Michael Dell took a shot at his old foe Carl Icahn Tuesday, mocking the investing legend's struggles this year in the latest twist in a decade-old feud between the two tycoons.

Shares in Icahn Enterprises, the holding company controlled by Dell's longtime rival, have cratered 63% this year. The tech billionaire made light of that by comparing the stock's performance to the benchmark S&P 500 over the past decade.

"During the last 10 years, Icahn Enterprises stock was down 80.7%," he said in a post on X. "S&P 500 was up 155.9%."

"What is the opposite of Play Nice But Win?" Dell added, referencing the title of his own 2021 autobiography, where he slammed Icahn.

In May, short-seller Hindenburg Research published a report where it disclosed it was betting against Icahn's company. It said the activist investor had deliberately inflated asset values and run his business empire using "Ponzi-like economic structures".

Since then the stock has cratered 54%, extending its losses for the past 10 years to over 80%, as Dell noted.

The billionaires' feud started in 2013, when Icahn tried to stop Dell from taking the PC company he founded private at a $24 billion valuation. Icahn built a stake and made a counter-offer, forcing Dell to eventually up his bid to $13.88 a share.

Icahn later described Dell's board as a "dictatorship" – and Dell responded by saying Icahn was "a bad guy" with "no ethical boundaries".

Tensions reignited five years later, when Icahn sued Dell in an attempt to scupper its attempts to go public. Icahn said Dell and his private equity backers Silver Lake were using "scare tactics" to try to get the tracking stock VMWare's shareholders to accept a buyout offer.

Again, the company was forced to renegotiate, upping its offer from 60 cents on the dollar to 80 cents on the dollar to secure the deal and take Dell Technologies public once again.