An assignment is the exact opposite of a choice exercise. When an option is assigned, the buyer or seller demonstrates the exercise of their respective rights. When an option is exercised, a seller or a buyer is chosen at random by the stock exchange's trading software to fulfill the contract. Consider that you sold a 400-call option on Tata Motors for a price of Rs 20. Tata Motors shares increased in value to Rs 440. It is feasible that a trader who purchased a Tata Motors 400 call might decide to exercise his option in such a situation. Now if there is a call, the loss incurred to honor the contract would be 40-20=20. No of whether the deal was profitable or unsuccessful, all option holders have the right to exercise their options.