The battle for quantitative talent has turned some of the richest money managers into underdogs. Why? Because they are up against the likes of Alphabet Inc.’s Google and Facebook Inc. for hiring the world’s top minds.

“Google is trying to hoover up every data scientist in the world,” said Luke Ellis, chief executive of Man Group PLC, the world’s largest publicly traded hedge-fund manager based in London. “Google has got more money than I have. I can’t compete with Google just on that.”

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