Benjamin is an asocial, solitary financier living in New York. Orphaned at 18, he abandons his family's tobacco business to pursue his true obsession: investing. He views capital as a living entity and operates on Wall Street with an almost inhuman dedication to profit, maintaining complete indifference to luxury or personal connection.

Helen is an intelligent, observant woman who grows up in an old-money family facing financial ruin. Treated as an object of study by her father and a party trick by her mother, she learns to retreat inward. She eventually marries Benjamin to escape her parents' control, using her new wealth to throw herself into philanthropy and the arts.

Andrew is a powerful fourth-generation New York investor who built a massive fortune during the 1920s boom and subsequent crash. He presents himself as a patriotic businessman whose trades benefit the American public. Extremely sensitive to criticism, he uses his vast wealth to shape reality, silence detractors, and craft an idealized public image of his life.

Mildred is Andrew Bevel's wife, characterized publicly by her husband as an innocuous, childlike companion who delights in domesticity. Behind this curated image, she is a deeply intellectual woman with a passion for avant-garde music, modern literature, and complex financial strategy. Her true personality and abilities sit at the center of the novel's central mystery.

Ida is an Italian-American writer who, as a 23-year-old during the Great Depression, takes a job ghostwriting Andrew Bevel's autobiography. Raised in Brooklyn by a militant anarchist father, she is pragmatic and observant, willing to fabricate details to secure her financial independence. Her investigation into the Bevel family challenges the historical narratives constructed by powerful men.

He is an exiled Italian anarchist and manual typesetter living in Brooklyn. Bitter about his lack of power and the rise of fascism in Europe, he rules his small household with strict, unspoken demands. He views finance as a corrupt fiction but relies entirely on his daughter's Wall Street income to survive.

Leopold is Helen's father, an intellectual who fails to gain the public recognition he feels he deserves. He channels his frustrations into aggressively tutoring his young daughter, treating her mind as a personal academic project. As his family's wealth dwindles, he falls into a deep, isolating obsession with esoteric theology.

Harold is an author and part of New York's artistic social circles. He writes a successful novel closely based on the lives of Andrew and Mildred Bevel, casting them as the fictional Benjamin and Helen Rask. His narrative deeply angers Andrew Bevel, prompting a massive financial retaliation aimed at erasing the author from literary history.

Jack is an aspiring journalist and Ida Partenza's boyfriend in 1930s New York. He talks grandly about reporting from the front lines of Europe but struggles to find actual work. He feels emasculated by Ida's high-paying Wall Street job and actively resents her financial independence.

Catherine is Helen's mother, a woman fiercely dedicated to maintaining her family's social cachet despite their evaporating fortune. Pragmatic and manipulative, she treats her daughter's intelligence as a parlor trick and aggressively orchestrates Helen's marriage to a wealthy financier to secure their social survival.

Dr. Frahm is the head doctor at a Swiss psychiatric hospital where Helen Rask seeks treatment. He employs unconventional, holistic methods like rigorous physical exercise and talk therapy. His approach brings genuine improvement to his patients but draws the ire of those who demand strictly quantifiable, scientific control.

Sheldon is Benjamin Rask's right-hand man and the public face of his financial empire. He possesses the ostentatious, gregarious personality that Benjamin entirely lacks, making him the perfect front man for Wall Street socializing.

Mr. Shakespear is a high-level subordinate in Andrew Bevel's financial empire. Operating from an austere art deco office, he acts as a rigid gatekeeper, administering tests and conducting initial interviews for the highly coveted secretarial positions within the firm.