Keynes' liquidity preference theory holds that individuals and firms demand to hold cash, or liquidity, for three main motives: transaction, precautionary, and speculative. The transaction motive refers to holding cash for daily transactions, while the precautionary motive involves holding cash as a buffer against unexpected events. The speculative motive refers to holding cash in order to take advantage of anticipated price changes in bonds and securities. Together these three motives determine the overall demand for money, or liquidity preference, in the economy. The interest rate is determined by the interaction of liquidity preference and the fixed money supply. When liquidity preference is very high, so that demand for money vastly exceeds supply even at very low interest rates, monetary policy