Lower-limit of the plot, set as (desired price/spot)
ul
Upper-limit of the plot, set as (desired price/spot)
xlab
X-Axis Label
ylab
Y-Axis Label
main
Title of the plot
...
Additional plot parameters
Value
Returns a plot of a custom vertical spread.
Black line: The profit(loss) at expiration.
Red line: The profit(loss) at (1/2) time "t" ~ half-way to expiration.
Blue line: The profit(loss) at inception.