作者stasis (流雨風雪)
看板Trading
標題Trend by Ed Seykota
時間Sun Oct 28 13:35:01 2007
Trends
The trend is your friend except at the end when it bends.
==
Most traders agree they like to be long strong instruments. Traders agree
less on the definition of strong. Some definitions of strong from the web,
include:
having strength or power greater than average or expected.
potent: having or wielding force or authority.
impregnable: able to withstand attack.
None of these definitions seem to fit stocks, bonds or futures exactly.
Trading instruments do not possess muscles or authority or even a physical
structure. So traders who use the term strength, really mean something else,
likely, trending up.
The preference for the word, strength over trending, may owe to the richness
and variety of gut associations people have with strong and the rather sparse
and obscure associations they have with with trend.
A trend is a general drift or tendency in a set of data. All measurements of
trend involve taking a current reading and a historical reading and comparing
them. If the current reading is higher than the historical reading, we have
an up-trend. If lower, we have a down-trend. In the improbable event of an
exact match, we have a sideways trend.
The direction of the trend depends upon the method we use to perform the
comparison. Real instruments fluctuate minute-to-minute, day-to-day and
year-to-year. We have, therefore an enormous supply of historical points to
use to determine trend. As such, we can determine as many instances of trend
as we please, in any direction that we please.
There is no such thing as the trend; there are countless trends, depending on
the method we use to determine a trend. People typically pick a method for
determining trend that fits with their current positions and/or view of the
market.
==
There's No Such Thing as an Uptrend Forever
Note: In the case of a monotonically increasing series, such as the balance
of a US dollar bank account with daily compounding interest, every price is
above all its predecessors. You can make a claim, then, that no matter how
you measure it, the trend is always up.
However, in a larger scope, in a world in which the US dollar fluctuates in
value relative to other currencies, and in which banks sometimes fail, a bank
account may not actually continue to be a long-term monotonic up-trend
investment.
Say we compound one penny at a three percent per year interest rate from year
Zero-AD to the present. We get about $5.48 * 10^23, or around a half
trillion trillion dollars. Clearly someone in those early days has a penny
earning interest, per stories of money lenders in temples. That no such
investment survives today indicates severe financial setbacks, from time to
time, in which people and whole societies experience collapse and have to
start over. Compounding interest seems to work pretty well for a few hundred
years at a time.
==
All methods of defining trends compare various combinations of historical
price points. All trends are historical, none are in the present. There is
no way to determine the current trend, or even define what current trend
might mean; we can only determine historical trends.
The only way to measure a now-trend (one entirely in the moment of now) would
be to take two points, both in the now and compute their difference. Motion,
velocity and trend do not exist in the now. They do not appear in snapshots.
Trend does not exist in the now and the phrase, "the trend" has no inherent
meaning. When we speak of trends, we are speaking, necessarily, from some or
another view of history.
There is no such thing as a current trend. When we speak of trends we are
necessarily projecting our own definitions.
With that in mind, we can proceed to examine ways to define, compute and use
trends.
--
而一首歌的寂寞 怎麼有人懂
http://blog.pixnet.net/stasis
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◆ From: 59.112.82.181
1F:推 HOTP:好文 好文~~(講到動態概念這件重要的事) 11/02 11:37
2F:推 rosebery:Ed Seykota的文章....建議引人的東西註明作者/來源喔 11/03 22:49
3F:推 stasis:啊 對不起 忘了附出處 11/04 00:07
※ 編輯: stasis 來自: 218.167.73.196 (11/04 00:09)