The true investor scarcely ever is forced to sell his shares, and at all other times he is free to disregard the current price quotation. He need pay attention to it and act upon it only to the extent that it suits his book, and no more. Thus the investor who permits himself to be stampeded or unduly worried by unjustified market declines in his holdings is perversely transforming his basic advantage into a basic disadvantage. That man would be better off if his stocks had no market quotation at all, for he would then be spared the mental anguish caused him by other persons’ mistakes of judgement.Benjamin Graham, The Intelligent Investor
In his book, Graham often points out the difference between investing and speculating. This paragraph is a wonderful reminder of what it means to be an investor. Market fluctuations are to be viewed as opportunities for making wise decisions, not avenues of stress, worry and speculation.