I was recently asked a question on Quora (“What does support level mean in a technical chart of a stock?“), and after I finished answering it, I realized it was way too long not to share here. So here it what I said:
Although I’m a chartist, I will answer this in “human” rather than chart-based terms. I’ll use a rather facetious example to make my point.
Let’s say a given stock X traded between $50 and $51 for two solid years. Countless people bought at that price. It was boring but very, very stable.
Now let’s say for whatever reason the stock vaulted swiftly over the course of a month up to $80 per share. Perhaps there were takeover rumors or optimism about a new product line. So now you’ve got a huge mass of people with nice fat profits, as well as some newcomers who paid between $51 and $80 for the same stock.
So now you have two classes of owners – – a large mass of folks with a good basis price and big profits, as well as newcomers whose profits range from decent to very small, depending on the price they paid. This latter group is going to be quite nervous and have weak hands. The former group will be more confident, since they have a much lower basis and have grown accustomed to the stock never being below $50. (more…)

