Of course, "best" is subjective, and in the world of investing, "best" really just means most suitable for you given your financial goals and risk tolerance. At the time of writing, SoFi has six ETFs: Each of these ETFs has its own purpose. SFY is the most popular, having a zero expense ratio and claiming to mirror the S&P 500. WKLY is the least volatile and unique in its weekly payments. GIGE has the most growth potential, focusing on the gig economy.