The same position from purchase to expiration. Press play, or drag to any day. Everything recomputes from Black-Scholes-Merton in the browser.
Curve shows position value against underlying price. The pale line is the expiration payoff, fixed. The solid line is theoretical value at the selected day, which converges onto it as time runs out - that convergence is theta.
Preset is a long 100 call. Change legs in the URL to view any structure. Reference only, not investment advice.