Social Finance

Founded: 2011

Valuation: $4 billion

Lending company Social Finance (often known as SoFi) raised $1 billion in September, helping establish CEO Mike Cagney's endeavor as one of the best-funded startups in Silicon Valley. The fundraising was the biggest financing round by any company in the fintech industry.

SoFi is up against other online lenders and brick-and-mortar banks alike. So far this year, the startup has lined up more than $4 billion in loans. That accounts for roughly 80% of its $5 billion in loans issued since its launch in fall 2011. Cagney believes there's a lot more room for its origination platform to grow.