Opinion of the Court 25-13631 ROSENBAUM, Circuit Judge: High-frequency trading in securities markets is technologically sophisticated and almost incomprehensibly fast. The dispute in this case centers on 350 microseconds, about one-third of one-thousandth of a second.1 That sounds fast—and it is—but it’s a long time for a high-frequency trader. Today, securities trading operates based on electronic orders that travel between data centers extremely quickly, but not instantly. When a security’s...