9. Mario Schlosser, Josh Kushner, and Kevin Nazemi

Cofounder and CEO (Schlosser), cofounder and managing partner at Thrive Capital (Kushner), cofounder (Nazemi), Oscar

In April, health-insurance company Oscar raised $145 million, giving it a $1.5 billion valuation. Then in September, Oscar closed another $32.5 million round of venture funding led by Google Capital, pushing its valuation up to $1.75 billion. With these investments, Oscar joins the ranks of buzzy startups known as unicorns, a moniker used to describe those with valuations over $1 billion.

Oscar wants to transform the healthcare industry by creating a better user experience when it comes to health insurance. It launched publicly in 2013 and had more than 40,000 customers across New York and New Jersey as of April, with plans to launch in Texas and California.