Investing legend Warren Buffett, chief executive of conglomerate Berkshire Hathaway ( BRK.B ) , has lavished praise for years on Ajit Jain, one of the company’s two vice chairmen.

The Indian-born Jain heads up Berkshire’s massive and lucrative insurance operations. The company's insurance revenue provides much of the ammunition for Buffett’s purchases of stocks and whole corporations.

Jain, who turns 73 on Sept. 15, has played a major role in Berkshire’s success in catastrophe insurance. He began at Berkshire in 1985 and was named vice chairman in 2018. Buffett is the chairman.

“Ajit insures risks that no one else has the desire or the capital to take on,” the Oracle of Omaha wrote in his 2017 letter to shareholders . Buffett lives in Omaha.

“His operation combines capacity, speed, decisiveness and, most important, brains in a manner unique in the insurance business. Yet he never exposes Berkshire to risks that are inappropriate in relation to our resources.”

Warren Buffett: Jain ‘handed the keys’ as novice

Though he came to Berkshire as a raw rookie in insurance, Jain was “handed the keys to our small and struggling reinsurance business,” Buffett said.

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“Since then, Ajit has created tens of billions of value for Berkshire shareholders. If there were ever to be another Ajit, and you could swap me for him, don’t hesitate. Make the trade!”

Despite his affection for Jain, Buffett has named Berkshire’s other vice chairman, Greg Abel, his successor. That may have something to do with Abel’s age—he’s 62, 10 years younger than Jain, while Buffett is 94.

Jain put his money where his desk was at Berkshire, buying stock with his own funds to become one of the company’s biggest individual shareholders.

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But now he has taken advantage of the stock’s surge to book some serious profits. Berkshire shares jumped 58% over the past two years, and its market capitalization breached $1 trillion last month.

Jain unloads Berkshire shares

Jain sold 200 Class A Berkshire ( BRK.A ) shares Sept. 9 at $695,418 a piece, giving him a kitty of $139 million, according to a regulatory filing.

The sale represented 55% of his stake: Jain still controls 166 shares. Of that total, he holds 61 directly and 105 through trusts and his non-profit Jain Foundation.

You might wonder what kind of signal is sent about the company with Jain selling so many shares. But news of the move hasn’t hurt Berkshire shares. They slid just 0.5% on Sept. 12, the day after the news came out.

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So why exactly did Jain sell Berkshire shares? There could be any number of reasons, including estate planning. The stock dump may not reflect his outlook on Berkshire at all.

Some experts say it might be a sign that Jain is headed out the Berkshire door.

"Those of us who have watched Berkshire Hathaway for a long time have suspected there may be a changing of the guard in insurance operations,” Cathy Seifert, an analyst at CFRA Research, told Reuters .

"My sense is that he may be moving on, and I suspect that is behind his stock sales.” She has a buy rating on Berkshire stock.

The author owns shares of Berkshire Hathaway.

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