Matthew Andresen built a remarkable career at the place where technology and finance meet. Back in the dot-com boom, he made his name as CEO of New York–based electronic trading network Island ECN, which was bought by Instinet Group in 2002.

Two years later he joined Citadel Investment Group, where he built and served as president of Citadel Execution Services, the $12 billion Chicago-based hedge fund’s market-making business. Now, having left Citadel last year, Andresen, 40, is on to his third act. He and two Citadel alumni have formed their own technology-focused trading business.

Unlike a hedge fund, Headlands Technologies, which has offices in Chicago and San Francisco, will not run outside money. It will develop rapid-trading strategies in liquid markets for its proprietary money, contributed by the founders and an unnamed financial backer. In time, Headlands may become a market maker in its own right, Andresen says: “Down the road, being a liquidity provider will be something that we will examine.”