Pre-sales for filmmakers involve selling parts of the film’s distribution rights to distributors before the film is completed, providing a promise of future revenue once the film is delivered to the distributors.
Gap option becomes available after other financing options, such as pre-sales, tax incentives, and grants, have been secured, but there is still a shortfall in the budget.
Even if a film looks like it will be a commercial success "on paper", there is still no accurate method of determining the levels of revenue the film will generate.
Fiscal sponsorship is a partnership between a film project and a nonprofit organization that allows filmmakers to receive tax-exempt status for their project.