Financial Planning explores the possibility of an IPO from the leaders in the robo-advice market including Betterment, Wealthfront and Personal Capital; the companies continue to raise money but some question the viability of the market; Betterment has over $10 billion in assets under management, Wealthfront has $7.4 billion and Personal Capital has $4.9 billion; the companies have a combined 420,000 clients and 548,000 accounts; article shares statements by each company regarding IPOs and the differences between the platforms. Source