Latest valuation: $500 million Threat to: SoFi, Better Mortgage, Quicken Loans' Rocket Mortgage Forbes on Blend: Blend Wants To Bring The $2 Trillion Mortgage Market To The Modern Era CommonBond Online lender refinances and finances undergraduate and graduate student loans. Emphasizes networking and even helps borrowers find jobs. Last year launched service that allows employers to contribute toward workers' student loan repayments, regardless of lender. Bona fides : CommonBond has made $1.5 billion in loans, but says just two have gone into default. Cofounder & CEO: David Klein, 37, started company with fellow Wharton MBAs.