Rokos Capital Management and Brevan Howard Asset Management were among a group of prominent hedge funds to suffer losses in July as sharp swings in artificial intelligence stocks disrupted strategies across the industry, according to a report by Bloomberg.

Chris Rokos’ firm fell 1.2% during the month, reducing its gain for the year through July to 8.1%, according to people familiar with the results. Brevan Howard’s Master fund also declined about 1.2%, leaving it up roughly 0.9% for the year.

Said Haidar’s Jupiter fund was hit harder, falling an estimated 3.2% in July and taking its year-to-date loss to about 13%, the people said.

The losses came after hedge funds enjoyed their strongest first half in five years, with a sudden reversal in AI-related stocks exposing crowded positions and creating large swings across markets.

DE Shaw was among the firms to navigate the turbulence successfully. Its Oculus fund gained 0.9% in July, taking its 2026 return to 27.7%, while the firm’s Composite fund added 0.4%, bringing its year-to-date gain to 13.9%.

The July selloff was triggered in part by concerns over the enormous capital spending commitments underpinning the AI boom. Nvidia’s announcement of more than $750bn in new AI-related deals fuelled questions over the sustainability of technology companies’ spending, while an unexpected advance by a Chinese AI developer added to concerns about the competitive landscape.

The turmoil was intensified by the collapse of AI-focused hedge fund Situational Awareness, which plunged 67% in July and was forced to sell most of its public-equity portfolio to Citadel to meet margin calls.

The fallout extended beyond technology-focused managers. Macro firms, traditionally associated with trading currencies, interest rates and other asset classes, have become increasingly active in equities, leaving them more exposed to sharp moves in stocks.

Brevan Howard, for example, has traded equities for more than two decades but has expanded its equity operation in recent years and built a team of sector specialists under strategist Abhijit Chakrabortti.

The dispersion in July performance was striking. Citadel’s Equities and Tactical Trading strategies gained 14.2% and 11.1%, respectively, while Renaissance Institutional Equities rose 9.2% and Quantedge gained 7.8%.

At the other end of the spectrum, several major managers suffered sizeable declines. Millennium fell 2.1%, Point72 dropped 3.3% and Marshall Wace’s TOPS strategy lost 2.6%. Coatue declined 8.3%, while Altimeter fell 11%.

AI-focused strategies were particularly vulnerable. Point72’s Turion strategy dropped 11.4% in July, while Whale Rock’s Long Only and Flagship strategies plunged 18.8% and 21.7%, respectively.

Despite the difficult month, many managers remain comfortably ahead for the year. Quantedge was up 34.6% through July, DE Shaw Oculus 27.7%, Citadel’s leading strategies about 27%, and D1 Capital’s stock portfolio 23.3%.