Warren Buffett steps down as chief executive of Berkshire Hathaway today, closing one of the longest and most consequential tenures in modern corporate history and forcing investors to confront whether America’s most venerated conglomerate can thrive without the man who defined it?

The retirement, announced at Berkshire’s annual shareholders’ meeting earlier this year, hands day-to-day control to vice-chairman Gregory Abel from January 1. Buffett, now 95, will remain chairman and has said he will still come to the office. But his exit from operational leadership ends a six-decade chapter that transformed a struggling textile maker into a sprawling financial colossus and reshaped the contours of American capitalism.

Today, Berkshire is the ninth-most-valuable company in the United States. It is the country’s second-largest property and casualty insurer, with tradeable stocks, bonds and cash worth nearly $700 billion, and it controls roughly 200 operating businesses. Those range from BNSF, one of America’s four “class 1” railroads, to a vast utilities portfolio and consumer brands such as Brooks running shoes and See’s Candies. The annual shareholder meeting in Omaha, anchored by Buffett’s marathon question-and-answer sessions, has long been treated by devotees as a kind of capitalist pilgrimage.

The Buffett method

Berkshire is often viewed as a monument to Buffett’s investing genius, though he resisted easy labels. He began as a classic value investor, buying companies trading below the accounting value of their assets, and later made some of the most lucrative growth bets of modern times. The most notable was Apple, accumulated between 2016 and 2018 and now Berkshire’s most profitable investment.

Buffett embraced the idea of economic moats, durable competitive advantages that allow companies to earn returns above their cost of capital. Berkshire owns Apple stock worth about $65 billion, Coca-Cola worth $28 billion, and regulated or brand-protected franchises such as Bank of America, valued at about $32 billion, Moody’s, worth roughly $13 billion, Visa worth about $3 billion, Mastercard valued at around $2 billion, and American Express, of which Berkshire owns about a fifth, valued at $58 billion.

His most important innovation, however, was not simply how he invested, but how he funded those investments. The 1967 purchase of National Indemnity, followed by GEICO and a large reinsurance operation, gave Berkshire access to insurance float, which are premiums collected before claims are paid. That pool of capital financed some of Berkshire’s biggest deals, including BNSF and the quarter stake in .