David Boies has only argued about a half-dozen cases at the U.S. Supreme Court. Still, for most Americans who know his name, the Boies, Schiller & Flexner partner will always be associated with two defining high court battles—Bush v. Gore and the fight over same sex marriage.

On the other hand, it’s safe to say that most Americans will never hear of Halliburton Co. v. Erica P. John Fund, which Boies argued back in March. But for corporations, or anyone whose bread is buttered litigating securities class actions, Halliburton was the big news at the Supreme Court this week.