Call Diagonal Calendar Spread

CDIAGCDIAG-E2_E1-X(E2)_X(E1)

Buy far call at strike A, sell near call at strike B (different strikes).

Near Expiry (E1)

Far Expiry (E2)

Strike X1 (low)

Strike X2 (high)

Hybrid of a calendar and a vertical spread. Plays the forward-vol curve plus directional bias along the smile.

Pick two expiries and 2 strikes to build the combo.