Tom Williams

Tom Williams said he was approached by several large Wall Street firms wanting to buy his program trading boutique, but he wouldn't sell. "I had no interest in merging with anybody," he said. "I enjoyed my independence."

Spear, Leeds, apparently, made an offer he couldn't refuse. "They are extremely good at allowing firms to retain their independent culture and to function autonomously at the same time," he said.

Williams, 45, is an alumnus of both the undergraduate and graduate divisions of the University of Pennsylvania. As an undergrad, he studied philosophy and mathematical logic; as a grad student, he studied artificial intelligence and computer science.

His introduction to Wall Street came in the hallowed halls of the old line New York Stock Exchange specialist, Wagner, Stott. His beat was proprietary index arbitrage, where he managed equity execution and also developed some electronic program trading technology.

He started TLW Securities in 1991 and joined SLK as a partner last year. "I couldn't be happier," he said.