PIK notes are debt instruments based on non-cash payment of interest coupons.
Interest is usually recognised by an increase in the amount of principal owed by the borrower.
PIKs are generally either unsecured loans or deeply subordinated securities ranking just before equity in the capital structure.
This means that, in the event of a bankruptcy, PIKs are the last debts to be repaid, making them a high risk instrument for lenders and investors.
In order to compensate lenders for the risk, PIKs have to offer significantly enhanced rates of return to investors.