The red surface shows Black-Scholes call values for a variety of stock and strike prices. A
Sequencer in the visualization shows the effect over time. You can
Pickon a location on the surface which selects of combination of stock and strike and reports the Black-Scholes value. Then you can run the sequencer to watch the price change. Note that at very high stock prices, the slope of the surface approaches 45 degrees. In other words a $1.00 change in stock price translates to a $1.00 change in call price. When strike and stock are close together, a $1.00 change in stock produces about $0.60 change in call value.