Can a Box Spread Be Used to Create a Synthetic Loan or Deposit?

Yes, a box spread can be used to create a synthetic loan or deposit. A long box spread (buying the lower strike synthetic future and selling the higher strike synthetic future) is equivalent to taking out a loan.

The trader receives cash upfront (the premium difference) and pays a fixed amount at expiration. A short box spread (selling the lower strike synthetic future and buying the higher strike synthetic future) is equivalent to making a deposit, where the trader pays cash upfront and receives a fixed amount at expiration.