For decades, these institutional allocators took roughly the same approach to managing the vast piles of cash under their control: They diversified by divvying up the money across asset classes — for example 40% in stocks, 40% bonds and 20% alternatives — then stuck with it by rebalancing now and again when things got out of whack.

AQR Capital Management is doubling down on a strategy that seeks to juice returns with leverage for its first new US mutual funds in four years.

Hedge funds are paid big bucks for making smart market bets. Yet these days, a simple feature of the financial plumbing — largely overlooked on Wall Street during the low interest-rate era — is helping juice industry returns.

The fate of stock options with a face value of trillions of dollars is being influenced by unusual trading activity in the S&P 500 outside regular market hours, new research has found.