I enjoyed your article , "This December, free up some time by ignoring these investing issues". A timely article. Well written. As a long term subscriber, I know that you live by these "principles" even when we pepper you with questions on target prices! :)
You didn't mention about what would make you "sell"! In other words, what are your exit strategies other than trimming your position sizes in those multi baggers!
I ask this b/c of my experience with Knight therapeutics, Payfare and a few others. Do you look at "opportunity costs" in your portfolio construction?
I value your words of wisdom, always!
We wrote an article on this topic, here, and the same principals apply. Essentially, other than for sizing, tax or portfolio management reasons, the main reason to sell is if 'something has changed'. Either unusually (new) weak execution, management changes, debt, competition, product failure, technology obsolescence, lower confidence and a host of other reasons. While not the 'best' reason, trusting one's instincts often can help as well. If a company continually over-promises and fails to deliver, it is not likely to do much, as other investors are just as frustrated. Selling is not an exact science, though. Keep in mind that every trade has a buyer who thinks the stock is going to go up. We think it is important to know both sides of the thesis. We would also ask ourselves, 'do I like this enough to buy more?'. If not, then that usually is a good sign to perhaps considering selling.