300 North Capital replaced Marsico Capital Management as asset manager on the fund.
According to SIG, the mandate will give the fund exposure to growth companies regardless of market capitalisation.
SIG head of investment research Adam Smears said that mid cap stocks are more inefficient and contain earlier stage growth companies than the large cap arena does.
"We believe that an All-Cap strategy should demonstrate expertise in this area," Smears said.
"300 North Capital does this, but their understanding of macro drivers complements this knowledge by helping them allocate to larger cap names in times of market turmoil."
300 North Capital, majority owned by Old Mutual (US) Holdings, is an institutional investment manager specializing in long-only small cap, small and mid cap, and mid cap US growth equity strategies.
