What is a bond?

A bond is essentially a certificate that represents a loan made by an investor to a borrower, typically corporate or governmental. When you purchase a bond, you are lending money to the issuer in exchange for a promise to receive periodic interest payments and the return of the bond's face value when it matures. This is a fundamental characteristic of bonds, making them debt instruments.

The option describing a bond accurately captures this function by emphasizing the promise to repay the principal amount borrowed along with interest, which is one of the primary reasons investors purchase bonds—seeking a reliable stream of income through interest and the security of getting their principal back at maturity.

In contrast, the other options describe different financial instruments or concepts. Ownership in a company falls under stocks, which represent equity rather than debt. A mutual fund investment pools money from many investors to buy a diversified portfolio of stocks and/or bonds, but it is not a bond itself. Lastly, lending money to individuals is a broader category of personal loans and does not specifically relate to bonds, which are instruments issued by public or private entities.