Text from The Intelligent Investor – a book by Warren Buffett’s Guru Benjamin Graham. For every chapter Warren Buffett himself has written a detailed ‘Commentary’…
Here is a piece from the Commentary on chapter ‘The Investor and Market Fluctuations’. Warren is critical of people who check the value of their stocks several times a day and feel panicky or jubilant by short-term fluctuations of their stock value. Check this:

In the late 1990s, many people came to feel that they were in the dark unless they checked the prices of their stocks several times a day. But, as Graham puts it, the typical investor “would be better off if his stocks had no market quotation at all, for he would then be spared the mental anguish caused his by other persons’ mistakes of judgment” If, after checking the value of your stock portfolio at 1:24 PM, you feel compelled to check it all over again at 1:37 PM, ask yourself these questions:

  • Did I call a real-estate agent to check the market price of my house at 1:24 PM? Did I call back at 1:37 PM?
  • If I had, would the price have changed? If it did, would I have rushed to sell my house?
  • By not checking, or even knowing, the market price of my house from minute to minute, do I prevent its value from rising over time?
The only possible answer to these questions is of course not! And you should view your portfolio the same way.
Source: Commentary on Chapter 8, The Intelligent Investor

~ Kaustubh