I replied the following as an answer to the question on the post title:
My workday is dedicated mostly to read. Mainly information about the companies I own: SEC fillings; conference calls; investors presentations; company reports; news; blogs… I sometimes email with a group of other investors and friends with whom we once in a while share ideas and information. I also monitor what other relatively famous investors I admire are doing. But there are just a handful I take seriously and I never make investing decisions without investigating by myself.
I mostly focus on the companies I own and where I have more doubts and continually reassess if I should keep on holding them. The good companies I have take care of themselves alone so I mostly focus on the ones that have the higher probability of having permanent capital losses.
I pass quite some time on companies that have had decreases in their share price. If I see that the company is doing Okay and the price fall is not justified I generally add, specially if I consider it to be quite undervalued. That’s the way I have added or bought several of the companies I have. A good company with good return on equity, financially solid and with honest management will probably do well in the future no matter how cheap you bought it. Since I focus on quality companies I do not spend much time thinking about what to sell, if a good company does not get grossly overvalued I just keep it. That saves me time. I don’t have to think so much about what to sell as about what to buy. I therefore focus on trying to find good value and trying to eliminate the positions that are at risk.
I pass long periods of time reading books. Mostly related to economy or investing. That entertains me a lot and makes me improve by leveraging on the experience of others.
I do not dedicate all my time only to investing activities. I sometimes pass days away from investing. In some periods like now after new year, when my kids are in vacation and the river and the weather is great I go swimming with them. Or I just lay on the garden in a hammock and look at the sky and the trees and sleep. Or I cook, or I make jewelry, a new hobby I have, or I play chess (seldom lately because I have the tendency to get addicted by it), write on the blog, etc… I never leave investing completely alone, at minimum I dedicate 3 hours a day to it, it just comes natural, I can not help it nor want to.
Then again most other weeks I pass the whole day just reading about investing with small breaks to the kitchen to eat. Specially during market extremes or when I get obsessed with a company I like. Fortunately my wife supports me with all the practical daily activities. If I did not have her it would be much more difficult to dedicate as much time to it.
Finally I also read about companies I do not have, in part because I enjoy it and also in order to be prepared to buy them if one day they get cheap enough. If you get a couple of good companies a year at good entry points you should do Okay. Companies in average have a lot of volatility in a given year. The difference between the year high and year low is around 50% or more. Therefore if you regularly study and are patient; reasonable; well informed and keep some cash available then you should be able to spot nice companies at good prices, at least sometimes a year, unless the market is too overvalued.