S-Shaped Function

Function

An S-shaped function is a mathematical curve that models how perceived value or utility changes with gains and losses, central to prospect theory. In financial derivatives, this function illustrates that individuals are typically risk-averse when facing potential gains but risk-seeking when facing potential losses. The curve is concave for gains, indicating diminishing marginal utility, and convex for losses, showing increasing marginal disutility. This non-linear relationship explains many behavioral biases. It deviates from classical utility theory.