The U.S. stock market operates in an increasingly opaque environment, where trading activities are conducted within tightly controlled facilities located in New Jersey and Chicago. This shift to "black boxes" signifies a transformation in how trades are executed, often relying on advanced technology and algorithms that many investors cannot see or understand.

In Michael Lewis's book "Flash Boys," the author highlights this trend of hidden trading practices, raising concerns about the fairness and transparency of the market. This environment favors a few sophisticated players, potentially leaving average investors at a disadvantage as they navigate the complexities of the modern financial landscape.