Financial terms of the deal were not revealed.
Portola, which oversees $5.2bn in assets, provides investment and wealth planning solutions to affluent families majorly located in San Francisco Bay area.
The firm also focuses on intersection of investments and tax, wealth transfer, estate, and charitable planning.
The acquisition expands CI’s footprint into the San Francisco Bay Area, which the firm counts as a significant area of technology-driven wealth creation.
CI CEO Kurt MacAlpine said: “Portola’s expertise and client focus have earned them the loyalty and trust of some the country’s most successful wealth creators, and we are thrilled to have the team join CI.
“Portola has developed wide-ranging capabilities to address the multifaceted needs of ultra-high-net-worth families, from intellectually rigorous, endowment-style investment management to complex tax planning to a wide range of family office services.
“The Portola team and model will be valuable in fostering the development of our ultra-high-net-worth offering across CI Private Wealth.”
Portola co-managing partner Zack Herlick said: “Joining with such a premier group is a big step forward in delivering on our two-part mission, doing what is right for our deeply valued clients and for our exceptional team.”
CI expects its US wealth management assets to reach around $82bn (C$103bn) following the completion of the latest and other outstanding acquisitions.
The firm’s total assets are estimated to reach approximately $263bn (C$331bn) globally.
In June this year, CI Financial agreed to buy Radnor Financial Advisors, which primarily serve HNW families in the Greater Philadelphia region of the US.