The market is a pendulum that forever swings between unsustainable optimism (which makes stocks too expensive) and unjustified pessimism (which makes them too cheap). The intelligent investor is a realist who sells to optimists and buys from pessimists.
Benjamin GrahamThe value of any investment is, and always must be, a function of the price you pay for it.
Benjamin GrahamObservation over many years has taught us that the chief losses to investors come from the purchase of low-quality securities at times of good business conditions. The purchasers view the good current earnings as equivalent to 'earning power' and assume that prosperity is equivalent to safety.
Benjamin Graham