Width

As explained above, a strategy might have one or more legs. Each leg has a strike. There is a family of strategies with two legs on the same strike: straddle, strip, and strap. These strategies have only one parameter – the strike.

All other multileg strategies require more information to be specified. For example, if we are building a vertical call spread, we have to select a strike(1) for the first leg (long call) and also a strike(2) for the second leg (short call).

Options strategy builder does not allow users to select both strikes directly. Instead, the user can choose the first leg strike and specify a distance (width) between strikes. This enables the user to change only the first strike while keeping the strategy nature unchanged.