Like Aspect Capital — another large London-based managed-futures firm — Winton Group traces its roots back to AHL, the giant quantitatively driven fund founded in 1987 and acquired by Man Group in 1989. Winton's founder and president, David Harding, is the "H" in "AHL." A physicist, Harding was an early pioneer in the commodity trading adviser (CTA) field. Today, Winton, which bears Harding's middle name, is the world's biggest managed-futures firm. CTAs proved critical in the 2008 downturn, generating large profits from capitalizing on price trends in futures markets and the surge in market volatility. Historically, Winton has a strong record of growth and high returns. The firm's flagship Winton Futures Fund…