Nygren grew up in St. Paul, Minnesota, and attended St. Paul's Harding High School. His father was a director of credit for 3M, known for its Post-it Notes and Scotch Tape products, and his mother was a stay-at-home mom.
From a very young age, Nygren had a fascination with numbers. Each day, he eagerly ripped through the St. Paul newspaper in search of sports statistics. A self-acclaimed baseball fanatic, Nygren would scour columns of data on batting averages and on-base percentages.
In 1965, when Nygren was seven years old, the Minnesota Twins and slugger Harmon Killebrew made it to the World Series against the Los Angeles Dodgers. Four of the games were played at Metropolitan Stadium, located about fifteen miles from Nygren's boyhood home. The stadium was demolished in 1985, and the site later became home to the sprawling Mall of America.
As it turned out, 1965 wasn't Minnesota's year. Sandy Koufax, the Dodgers' pitching ace, silenced Minnesota's bats in the seventh game of the series, leading Los Angeles to a dramatic 2-0 victory and the world championship.
Just as his father's gambling lesson had led to an unexpected result, so, too, did Nygren's unyielding devotion to balls and strikes. As Nygren grew older, his eyes would often drift from the box scores to the business section's stock charts, which were located on an adjoining page of the newspaper. Though he didn't know much about what the numbers and fractions represented, he scanned them anyway.