Gemini has appointed former Kraken CEO Mark Jennings to head the exchange’s European unit, among several key senior hires.

Cameron and Tyler Winklevoss discuss why their new venture, SumZero, makes good business sense right now. Photo: Joe Fornabaio/The Wall Street Journal.

Many of your career goals and big-picture dreams that once felt like distant visions on the horizon are now becoming tangible, within your grasp. This moment calls for your willingness to act, to ...