Forecasting foreign exchange rates is notoriously
difficult. Economists dont have a standard model of what determines
exchange rates, and even the most brilliant and closely-reasoned
forecast can run off the tracks as events unfold. But multinational
corporations and global fund managers must have forecasts in order
to select foreign activity priorities and to protect against catastrophic
loss.
Exchange rates tend to be more highly trended than other financial
price series (such as individual equities). This is because the
institutional and economic variables underlying exchange rates tend
to move slowly, such as relative inflation rates.
Technical analysis based on statistics
constantly identifies market trends.
Companies hedging an underlying business position
are given clear advice on whether to buy or sell.
Even so, exchange rates are not always trended,
which has two critical
consequences for the international firm:
- First, the manager has to decide
whether technical analysis is correctly identifying a trend. The
best way to make that judgment is to determine whether techni-cal
signals are consistent with the Big Picture fundamentals.
- The second critical issue is what
to do about a new signal; this entails a re-evaluation of the
firms exposures, and the risks and rewards of taking alternative
actions.
So, knowing the context of the decisions at
hand is of paramount importance. There is no single correct answer
to the question Where is the Japanese yen going?
First, we need to know the timeframe over
which the answer will be applied - uncertainty increases geometrically
with distance into the future.
Fundamental economists may get the direction
of exchange rate moves right, but they hardly ever get the timing
right. A solution to this problem is technical analysis, which uses
statistics to identify trends. The premise of technical analysis
is that the price alone contains all the information we need to
know about market sentiment, and a trend once in place will continue
until something comes along to reverse it. That something
can be a government policy change, new information about the state
of an economy, or just a fresh way of looking at a currency. Whatever
factor is dominant at the moment doesnt matter: the price
reliably reflects the sum of market perceptions about the currency.
In our Japanese yen example, the intermediate
model system may be showing that the yen is getting stronger and
should be bought or hedged, while our long-term system shows that
in a wider timeframe, it is weakening and should be sold. To reconcile
such discrepancies, we consult the Big Picture fundamental
economics - with an eye on the firms exposure.
Foreign exchange management is a continuous
process of trying to hit a moving target. The Rockefeller approach
is to use all available tools, fundamental and technical, to achieve
excellence in the management process. We define excellence not as
being right more than 50% of the time, a common misconception,
but rather always knowing the range of possible outcomes, i.e.,
reducing uncertainty over the chosen timeframe.
The Rockefeller Methodology
We employ a highly disciplined quantitative
methodology. Technical analysis can be of several different
types, including cycle theories, neural networks, and
other schools of thought. RTS has designed its proprietary technical
analysis system using a combination of well-tested statistical modeling
techniques.
Each currency has a customized set of models,
which are weighted and combined in a confirmation approach.
Two of the models use the moving average crossover concept, whereby
the current spot price rising above various moving averages generates
a buy or uptrend signal. Moving average
models are the workhorses of statistical analysis and are robust
in identifying new trends-- but they are backward looking, or lagging
indicators.
The second valuable concept in statistical
analysis is momentum, which captures the rate of change in a price
series. This is a current indicator; a price moving up with greater
acceleration is statistically more significant than a price moving
more slowly.
We use two momentum models for each currency.
Finally, we wish to measure volatility. A period of low volatility,
in which a price moves significantly less than its statistically-defined
average true range, usually precedes a breakout either
up or down.
Volatility models are forward-looking; we
use two volatility measurement models. We weight each of the models
and generate buy/sell signals based on the sum of the weights. These
models were designed and developed in 1990 and have been little
changed since; they are simple and powerful, and tend to remain
successful as the global environment changes over time.
Our modeling system is scientific in the sense
that anyone using the same price series and the same statistical
models could replicate it. Technical analysis out performs human
judgment over long periods of time, even when new signals may seem
to be counter-intuitive. We never override the system output with
judgment. The decision to ignore, or override a technical signal
belongs to the client, and we offer commentary and consulting to
refine that decision. |