Treasury bills, commercial paper, certificates of deposit, repurchase agreements, and banker's acceptances are some of the main money market instruments. Treasury bills are issued in maturities of 91, 182, and 364 days and are considered very safe since they are issued by the central government. Commercial paper and certificates of deposit are issued by corporations and banks for maturities between 7 days and 1 year. Repurchase agreements and banker's acceptances also have short maturities, with repos being used for overnight borrowing and banker's acceptances having maturities of 30-180 days on average.