Dalio’s latest choice is David McCormick, the firm’s president, who has been at the firm since 2009. A West Point graduate who once worked under George W. Bush, he was poised to join the Trump administration as deputy defense secretary, but withdrew his name, in part because of friction with his future boss, Defense Secretary James Mattis. He will join Eileen Murray, who has been at the firm eight years and co-CEO for four. Dalio plans to hand responsibility of Bridgewater to a team rather than a single leader.

"I’m excited about this change and expect to remain a professional investor at Bridgewater until I die," Dalio said in the post Wednesday. “Or until those running Bridgewater don’t want me anymore.”

Rubinstein’s appointment to Bridgewater was a head-scratcher for people close to the tech executive, according to someone who knows him, since his background was in consumer-electronics hardware. He left Apple in 2006 and later became CEO of Palm Inc., the maker of a once-groundbreaking handheld digital assistant. He stayed at Palm after it was acquired by Hewlett-Packard.

Dalio has taken his time ceding control of the firm, saying it would take a decade for the transition to occur. In 2011, he said he was stepping down from day-to-day management, and took on the role of “mentor,” though he kept his job as co-CIO. Since then, returns have averaged just 3.5 percent annually, a far cry from the double-digit gains Bridgewater produced earlier in its history. Assets have fallen below their peak of $169 billion in 2015 as investors decamped.

Early Years

Dalio stepped in again as interim co-CEO last year after his disagreement with Jensen, who joined the Westport, Connecticut-based firm more than two decades ago as an intern.

The son of a jazz musician and a stay-at-home mom, the Long Island native started Bridgewater in 1975 out of his apartment. At first it was an investment research firm focusing on risk management and macroeconomic data. He later started managing money for pension plans, using investment formulas he’s developed over the past four decades to make calls on currencies, commodities, stocks and bonds.

The firm, which he describes as an “intellectual Navy Seals,” is ruled by 210 principles, rules of the road that range from “Don’t try to please everyone" (210) to “Don’t pick your battles, fight them all” (96).

Roving Raters

Employees carry around iPads with apps that allow them to rate each other on their contributions. Each worker has a “baseball card” with their ratings for various attributes. One key project underway at Bridgewater is developing algorithms based on employee data to help automate decision-making at the firm.