Pi is a 1998 psychological thriller directed by Darren Aronofsky. The film follows a troubled mathematician, Max Cohen, as he struggles to make sense of the mysterious patterns he discovers in the stock market. As Max's obsession with the patterns grows, he finds himself in a dangerous game of
From Wikipedia
The number π is a mathematical constant, approximately equal to 3.14159, that is the ratio of a circle's circumference to its diameter. It appears in many formulae across mathematics and physics, and some of these formulae are commonly used for defining π, to avoid relying on the definition of the length of a curve.