Carl Icahn loves working. Which means he is always game for a speculation that usually results in a profit.

The long-time activist investor (sometimes known as a corporate raider) has acquired a stake in gaming giant Caesars Entertainment  (CZR) . Bloomberg News first reported Icahn has built "a sizeable stake" in the gambling company on Friday.

Icahn has not yet filed a statement of his holdings with the Securities & Exchange Commission. He did tell CNBC's Scott Wapner that he liked Caesars and "I own some stock" in the company. 

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The news reports generated some heavy trading in Caesar's on Friday. Some 26.1 million shares changed hands, pushing the stock up 11.7% to $35.56 in New York Stock Exchange trading.

An investor in a public company must report ownership after acquiring 5% or more of a class of the company's shares.

The average volume over the prior 21 sessions was just 4.5 million shares. But 7.3 million shares changed hands on April 30, and 11.6 million shares traded on May 1.

When Carl Icahn calls, you listen

Icahn is a billionaire many times over. Forbes magazine currently estimates his net worth at $5.4 billion.

And Icahn's name is one that corporate executives fear.

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He has made most of his fortune by taking big stakes in companies, demanding changes in how the companies are run and profiting when the company sells out to another, buys him out, or makes other changes to boost the stock price.

This is his second involvement in Caesars. The first came in 2019 when he acquired 10% of the stock and pushed the company to sell itself. The company agreed to add three Icahn nominees to its board of directors.

Later, the company sold itself to El Dorado Resorts. El Dorado then renamed itself Caesars.

Icahn is probably investing in Caesars again because the stock is down 24% in 2024 and has fallen 41% since hitting a 52-week high of $60.25 in July 2023. He says he's not interested in playing activist demanding change, but one never knows.

The shares were at $39 when the stock market bottomed in October 2023, then rose to as high as $50.51 in December.

The shares, however, have sagged ever since. The Standard & Poor's 500 Index is up 28% since the October low.

The company operates some 50 properties around the country. Caesers is a component of many exchange-traded funds including the First Trust Consumer Discretionary AlphaDEX Fund  (FXD) .