Darin Oduyoye, a spokesman for JPMorgan, declined to comment on behalf of the bank, Highbridge, and its Brazilian subsidiary Gávea Investimentos.
Highbridge has also undergone changes at or near the top. Billionaire co-founders Glenn Dubin and Henry Swieca are no longer in control as part of what Dubin said last year was an orderly "succession plan."
Swieca left to launch his own firm, Talpion Fund Management, in 2010 after serving as Highbridge's chief investment officer from inception in 1992 to its full sale to JPMorgan in 2009 (Talpion is now a family office).
Dubin has also pulled back. In July 2013, the firm announced that Scott Kapnick had replaced Dubin as CEO. Dubin remains at the firm as chairman and is now running his own family office, Dubin & Co., which is still invested with Highbridge. He is also an active philanthropist.
"I am delighted to be taking this next step in the evolution of the Highbridge franchise. After more than 20 years at the helm, I have decided that it is time to step away from my day-to-day activities as CEO of the firm," Dubin said in a statement at the time. "I will continue to remain active in my role as chairman and provide the firm with strategic advice and business counsel."
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There have been other departures as well.
In March, The Wall Street Journal broke news that Adam Bernstein, a technology sector head, and Mark Hoffman, head of stock trading, were preparing to leave to launch their own hedge fund.
Another to depart this year is Kristopher Drankiewicz, a technology and healthcare portfolio manager who worked at Highbridge since 2007. He has founded a new firm, Madera Technology Partners, according to his LinkedIn profile.
There were other notable departures in 2013. The most senior was Todd Builione, Highbridge's president and CEO of its hedge fund business, who left in July for KKR. Amy Yates Capone, the firm's more junior chief administrative officer, left in October to found her own human resources consultancy.
Other exits in recent years include Catherine Vaughn, the head of investor relations who left for Hutchin Hill Capital in 2012, and Carl Huttenlocher, the head of Asia who left to launch his own hedge fund Myriad Asset Management in 2011.
None of the recent departures responded to a request for comment.
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To be sure, there does not appear to be a mass exodus and some churn is expected at a large organization. Highbridge has actually grown recently, from 303 employees in May 2013 to 318 as of May 9, 2014, according to a person familiar with the firm.
In fact, Highbridge has hired 10 portfolio managers and their respective teams in the last 12 months from well-known private investment firms like SAC Capital Advisors, Millennium Management, Claren Road Asset Management, York Capital Management and Shumway Capital, according to the person.
For example, Highbridge recently hired two portfolio managers from SAC—Wayne Chambless and Christopher Procaccini. The move was first reported by The New York Times.