周末灌水，再贴两个看顶新图。

sfbayarea

谢谢ReadOnly 和 队长的分析  

dommy

美国经济现在是处于recovery phase。如果要对比经济数据的话，要用同样处于recovery phase的经济 ...
ypm968 发表于 2010-12-19 19:01

ranchgirl

从数学上讲没错。但使用对数坐标有一个隐含的前提，即经济是以几何基数增长。这在某个特定的历史时期可能是成立的，放在现在的经济条件下俺觉得大错特错。
Read0nly 发表于 2010-12-20 21:35

Can you provide a link about your "使用对数坐标有一个隐含的前提，即经济是以几何基数增长。"

I don't understand it, and could not find it. Thank you very much!

Read0nly

Can you provide a link about your "使用对数坐标有一个隐含的前提，即经济是以几何基数增长。"

I  ...
ranchgirl 发表于 2010-12-21 09:21

See this "logging tends to convert multiplicative relationships to additive relationships, and it tends to convert exponential (compound growth) trends to linear trends." from http://www.duke.edu/~rnau/411log.htm.

That means when you draw lines on log-transformed charts, you assume the underlying target to have an "exponential" curve in its regular formation. This is a bold assumption in terms of economic growth, because a logistic curve may fit the economic growth model better than a logarithm transformation.  

The only advantage of using the log-chart in investment analysis is to make reading the return folds visually much easier than from the regular chart.

Just my 2c. Please correct me if I'm wrong.

ranchgirl

回复 45# Read0nly
404 - Page Not Found

ranchgirl

See this "logging tends to convert multiplicative relationships to additive relationships, and it tends to convert exponential (compound growth) trends to linear trends
Read0nly 发表于 2010-12-21 14:36

Even I am not math major, but I know this is mathematically correct.

That means when you draw lines on log-transformed charts, you assume the underlying target to have an "exponential" curve in its regular formation. This is a bold assumption in terms of economic growth, because a logistic curve may fit the economic growth model better than a logarithm transformation.  

This is obviously incorrect or very very wrong. If you go to stockcharts.com, all stock curves are in log-chart, and none of them have an "exponential" curve.

Your "That means" drew a wrong conclusion.

Read0nly

hi ReadOnly, you still look for top>? should I cut-loss on my short positions? thanx
mindymore7588 发表于 2010-12-21 14:57

Yes. I still hold my short positions. If you get no margin calls, I would suggest you to hold your short position a few more days till after the new year to avoid the potential "covered on the top" error. Or you may consider to cover a portion of your short positions to reduce the risk. And try take some time to learn how to hedge when having a short position. You may find many free and useful books (PDFs) from Snowboy's book collections. He is one of the BZs of Da4Qian1Gu3Tan2 of Wenxuecity. Hope this helps.

Read0nly

Even I am not math major, but I know this is mathematically correct.


This is obviously inco ...
ranchgirl 发表于 2010-12-21 15:05

For the link, remove the "dot" in the end of the link. Sorry for the typo.

You are partially right that in "stockcharts.com, all stock curves are in log-chart, and none of them have an exponential curve." I forgot to mention that when I said it that way I meant the long-term charts. BTW, I have opted  to use regular chart format from Stockcharts for many years. For a short-term analysis, the market/stock curves do vary in many different patterns rather than a simply linear pattern after a logarithm transformation. However, the assumption of the underlying target to have an "exponential" curve remains unchanged in this situation, particularly when you draw lines attempting to determine local tops and bottoms. Technically, the shorter the time frame, the smaller the difference between the 2 types of charts, just like the MAs and EMAs.

henggma

wsjboy

顶，顶顶，顶顶顶

jamesmith

"Nobody can catch all the fluctuations. In a bull market your game is to buy and hold until you believe that the bull market is near its end. To do this you must study general conditions and not tips or special factors affecting individual stocks. Then get out of all your stocks; get out for keeps! You have to use your brains and your vision to do this; otherwise my advice would be as idiotic as to tell you to buy cheap and sell dear. One of the most helpful things that anybody can learn is to give up trying to catch the last eighth-or the first. These two are the most expensive eighths in the world."  - Jesse Livermore

hunting

回复 54# jamesmith


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