A co-founder of $750 million quantitative hedge fund shop Menta Capital has left for personal reasons.

George Patterson said that he remains an investor in Menta, and is seeking new opportunities in the asset management business, including opportunities outside of the hedge fund industry, according to published reports. He also said that the San Francisco-based firm has suffered alongside its fellow quants over the past several months.

“January was not a pretty month,” he said. “I don’t know the exact numbers because I’m not involved directly with Menta anymore. It was a tough month, but that was not just for Menta; it was across the board.”

Patterson founded Menta with a pair of fellow Barclays Global Investors portfolio managers in 2006.