People are talking buying force and selling force. 買賣心裡為內力。看漲才買，越買越漲，漲到一定程度就會覺得貴了，多數人開賣，股價就會迭，越迭越賣。跌倒一定程度，有人就會覺得便宜了，開買，股價就會停迭，即而反彈。大家觀望時就會出現Side way. 　看chart多了就會領悟股價波動的脈絡。News release, geopolitical events, etc. 為外力。　外力的作用有兩方面的。227的impact就是外力。That evening I checked the largest decliners, really scarry. Quite some stocks declined 20 - 60%!!! Luckily enough, on my account all of the stocks behaved just like a normal day. Look at today's index chart, it was so right that I sold all of the stocks on 228 only at about 1% down from 266. So, it is fun to play with the internal force. Every day's price is mostly influenced by the previous day's price (or previous several days') if there is no external force on action. To me the real risk is over night news or the day like 227.

In my work I have to deal with various scientific and engineering variables. They look very much like stock charts. For instance, it is a natural feature to have higher highs and higher lows for a fluctuating and upwarding variable. Please pull out a one year temperature chart from the internet. If you label it as ??.com's stock chart, those analysts would think so. In our research campus we have some high concret buildings. When it rains and the building walls are partly wetted, the wetted pattern is just like a stock chart.