Time deposits (also called certificates of deposits, or CDs) are nontransaction deposits at banks. Checks cannot be written on these accounts, and they carry substantial penalties for withdrawal before maturity, which can range from a few months to 5 years. In return for sacrificing liquidity, savers earn higher rates of return on time deposits than on savings accounts. Time deposits are a major source of funds for banks. Time deposits of less than $100,000 are generally nonnegotiable. They are not liquid, unless one is willing to pay the rather costly penalty for early withdrawal. Time deposits of $100,000 or more are negotiable and can be traded in secondary markets before their maturity, making them liquid.