The investment round brings the company's total equity funding to $1.9bn. The company plans to use the funds to accelerate its expansion into new product areas and countries outside of the United States.
Additional investors in the company's fundraising include SoftBank Group and GPI Capital.
SoFi co-founder, Chairman, and CEO Mike Cagney said: "We've seen tremendous growth at SoFi because we know what people expect from their financial partner: they want speed, transparency, and alignment with their interests.
"We're the only personal finance company focused not just on people's money, but their careers and relationships as well. We know this opportunity doesn't just exist in the United States, and look forward to bringing the SoFi approach to finance to more people around the world.
“Silver Lake's global relationships, technology expertise and value creation capabilities will be an invaluable addition as we expand our business further."
Silver Lake managing partner Mike Bingle said: "SoFi's platform — equal parts technology, community, and exceptional customer experience — is rapidly transforming personal finance.
"We are thrilled to partner with Mike Cagney and his talented team, and we look forward to helping SoFi achieve its long-term vision of offering a broad suite of financial services around the world."
SoFi closed 2016 with another strong year of growth, originating $8bn in loans, up from $5bn in 2015, and expanding its member base to 225,000 from 100,000 over the same period. It expanded its product offering in lending with the introduction of a first-of-its-kind Student Loan Payoff Refi for home mortgages and student loans in partnership with Fannie Mae.
In addition to new lending products, SoFi introduced its SoFi at Work brand for employee financial wellness, SoFi Wealth for modern investment management, and a partnership with Protective to offer term life insurance. Lastly, SoFi added considerable talent to the company, growing its headcount to 750 at year's end from 515.
In 2017, SoFi will take on new areas of personal finance and new geographies. With the recent acquisition of Zenbanx, the company plans to introduce a suite of mobile deposit, credit, and payment products to its members in the United States this year.
SoFi also plans to bring its lending products to people in Australia and Canada by the end of the year.
The transaction is subject to customary closing conditions.
