Build a bull call spread by price region

State compatible original legs

Both fictional calls share underlying, expiry and one-unit quantity. The 90 call is long and the 110 call short. Net premium paid is 12−4=8.

Compute the piecewise payoff

For S≤90, payoff is zero. For 90<S<110, payoff is S−90. For S≥110, subtracting the two call payouts leaves 20. Simple profit is each amount minus 8.

Reconcile the boundaries

Keep the spread limits conditional

Under these net-debit inputs the simple loss floor is −8, gain cap 12 and crossing 98. Those values are not an option-price model, an annual return or a recommendation to use the strategy.