The billionaire investment tycoon took a loss of more than $1.8 billion as he dumped his entire stake in the bankrupt rental-car company in recent days, according to court filings.

Icahn, 84, sold his 55.3 million Hertz shares at 72 cents apiece for just under $40 million on the heels of the Florida-based firm’s bankruptcy filing, records show. That looked like a pittance, given that he had amassed the 39-percent stake over a six-year period for an aggregate price of $1.88 billion, according to a March securities filing.

Icahn acknowledged that he dumped his position at a “substantial loss” that he did not quantify. But he left the door open to investing in Hertz again once it emerges from the Chapter 11 bankruptcy process.

“I believe that based on a plan of reorganization that includes new capital, Hertz will again become a great company,” Icahn said in a statement Wednesday. “I intend to closely follow the company’s reorganization and I look forward to assessing different opportunities to support Hertz in the future.”

Hertz shares plunged as much as 20.6 percent Thursday to $1.04 following news of Icahn’s exit. The Icahn Enterprises founder had invested in the 102-year-old company since 2014.

Hertz filed for bankruptcy protection last Friday as the coronavirus pandemic ravaged its car-rental brands. Wall Street sources have said the company could be sold for parts as its various components could fetch more than $2 billion, The Post reported last week.