Enlarge / Redfin CEO Glenn Kelman (credit: Randy Stewart) Shares of high-tech real estate brokerage Redfin surged on their first day of trading Friday. Initially offered for $ 15 per share, the company’s stock had soared above $ 20 by early afternoon, valuing the company at more than $ 1.5 billion. Founded in 2004, Redfin pioneered the concept […]