You can't. An IOU is a written document indicating the relationship between creditor's rights and debts, which is generally written and signed by the debtor, indicating that the debtor has owed the creditor the amount indicated in the IOU.

Financial instruments refer to financial assets that can be traded in the financial market, and are written documents to prove the balance of funds between borrowers and borrowers. The most basic elements are the amount paid and the terms of payment.

Financial instruments such as stocks, futures, gold, foreign exchange and insurance policies are also called financial products, financial assets and securities. Because it is a product that can be bought and sold in the financial market, it is called a financial product; Because they have different functions and can achieve different purposes, such as financing and hedging, they are called financial instruments. In the qualitative and classification of assets, they belong to financial assets, so they are called financial assets; They are legal documents that can prove the relationship between property rights and creditor's rights and debts, so they are called marketable securities. Most financial instruments or products, assets and securities have different degrees of risk.