A PIK or PIK loan is a loan characterized by the fact that the payment of interest Interest An amount paid in remuneration of an investment or received by a lender. Interest is calculated on the amount of the capital invested or borrowed, the duration of the operation and the rate that has been set. is not necessarily made in currency. The interest can be paid, for example, in the form of another debt security, by securities issued by the borrowing company or via the issuing of stock purchase options.