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Daily Speculations The Web Site of Victor Niederhoffer & Laurel Kenner Dedicated to the scientific method, free markets, deflating ballyhoo, creating value, and laughter; a forum for us to use our meager abilities to make the world of specinvestments a better place. |
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01/03/05
Time and Deformation, by Dr. Brett Steenbarger
Driving
along California's Route 1, connecting San Francisco and L.A., is
conducive to uplifting speculation and, indeed, recently prompted me to reflect
upon the market-related lessons I have learned in the past year. Perhaps the
greatest lesson concerns the role of time as a market variable and, in
particular, how deformations of time -- resulting from both market and personal
activity -- impact trading behavior.
My lesson began when I observed that highly capable traders who specialized in
one market consistently lost money when they tried their hand at different
markets. Struck by the contrast of outcomes, I began to follow and
simulation-trade two expressly different markets (let's call them A and B). My
observation was that B displayed far greater non-stationarity than A. In other words, the
time series of price changes during period 1 was far less likely to resemble the time
series of price changes during adjacent period 2 for B than for A. Dramatic swings
in volume and volatility -- as well as price direction -- in B made it quite different
to trade than A.
The interesting phenomenon was that, while the markets traded differently, the traders'
trading styles did not adjust for this. Some firms employ software that closely tracks
trader behavior, providing metrics for such variables as number of trades (long and short),
average holding periods of trades (long/short, winning/losing), time periods between
trades, etc. Apparently, the metrics for the A traders did not significantly vary when
they shifted to trading B; nor did they vary greatly from one period of the B trading day
to another, despite the clear variations (non-stationarities).
My next observation was that B traders who were more successful were more apt to shift their
trading styles and frequencies according to market conditions than those who were less
successful. The less successful traders tended to have an invariant style that sometimes
fit market conditions, but often did not.
To use Benoit Mandelbrot's phrase, market activity deforms time, creating a difference between
operational time -- the time it typically takes a market to move a given distance -- and chronological
time. Volume and volatility speed the market clock, but traders tend to function on chronological
time. I suspect traders run afoul of ever-changing cycles precisely because of the inevitable
chasms that separate chronological time from market time: chasms that are wider in some markets
than others.
A related observation is that just as market activity and inactivity shift the
operational clock, the trader's own activity and inactivity seem to alter his
perception of time: the internal, subjective clock. When a trader is actively
trading, perceived time is compressed; when a trader is out of the market, time
passes far more slowly. Many emotional reactions of traders that affect trading,
including impulsivity, anxiety and boredom, appear to spring from the subjective
deformation of time that results from shifting periods of activity and
inactivity. I recall a trader I knew who would regularly scream at his
screen, fuming about markets that would "stop trading". When I sat by the trader
to observe his trading, I noticed that he would put on large positions when
markets were active and then would feel time dragging as volume returned to its
mean. Subjectively, he felt trapped in his trade despite the fact that the
market was actually moving his way -- just not at his subjective pace.
It is little wonder that discretionary traders fare so poorly in the markets as a group. Between
the time deformations imposed by changing market cycles and the time distortions imposed by our
own subjective calibrations, it is difficult to truly "follow the market". We tend to treat
time as a constant, in our charts and in our research. I suspect, however, that it is precisely
the variability (and relativity) of time that imparts challenge to trading.