Modelling and Forecasting Volatility of the BRICS Stock Markets: Evidence Using GARCH Models.
Modeling and Forecasting Volatility in Foreign Exchange Markets
-
Upload
independent -
Category
Documents
-
view
1 -
download
0
Transcript of Modeling and Forecasting Volatility in Foreign Exchange Markets
Modeling and Forecasting Volatility in Foreign Exchange Markets
Sylwia Nowak
School of Economics, Australian National University
Sirimon Treepongkaruna*
School of Finance and Applied Statistics, Australian National University
Abstract
This study examines the properties of the GARCH model and its usefulness in modeling and
forecasting the volatility of exchange rate movements. The study adopts an approach to
forecasting out-of-sample that avoids any look-ahead bias. We find that the performance of
the forecast varies and depends upon the estimator of the latent volatility. An averaging
procedure produces superior forecasts compared to the standard practice of using daily point
estimates, however, the magnitude of the errors remains a concern irrespective of the method.
Moreover, across currencies and choice of metric, the out-of-sample analysis confirms how
difficult it is to forecast exchange rate movements.
JEL Classification: C220; F310; G150
Keywords: Foreign exchange rates; ARCH; financial time-series; volatility
* Corresponding author: College of Business and Economics, Australian National University, ACT 0200, Australia. Ph: +61-2-6125 3471, Fax: +61-2-6125 0087, [email protected].
2
Modeling and Forecasting Volatility in Foreign Exchange Markets
1. Introduction
Two assumptions generally made in the study of financial markets are that future returns are
independently and identically normally distributed and that their variance is constant through
the time. These assumptions conveniently lead to models of price movements that incorporate
only first-order moments. However, there is now a large volume of empirical evidence that
demonstrates that neither assumption generally holds in the context of risky assets. For
instance, empirical distributions of returns often exhibit leptokurtic properties. Further,
analysis of volatility typically shows that it varies through time and is prone to periods
of clustering. That is, large (small) changes in price to be followed by other large (small)
changes, in either direction (Bollerslev, 2001).
To account for these so-called ‘stylised facts’, researchers have incorporated time-varying
second-order moments into various models, popularly through the family of ARCH processes.
There has been considerable prior research that has examined the fit of ARCH processes in
relation to financial asset prices.1 Generally this research has attempted to find models of best
fit, with some research dedicated to an examination of the predictive ability of the various
models.
1 For comprehensive reviews of the literature, see Bollerslev et al. (1992) and Engle (1993 and 2002b).
3
For a time-series model to serve a useful purpose in practice, it should generally provide out-
of-sample forecasts that are of some predictive value. Volatility forecasts are particularly useful
in the investment and funds management industry for the purposes of portfolio construction,
security valuation and risk management; and the financial services industry for treasury
operations where estimates are required for managing portfolio positions through models such
as Value-at-Risk. Further, volatility is often a critical input for the valuation of derivative
instruments. However, there remain divergent views on the most appropriate model
of volatility. For example, Poon and Granger (2003), who provide a comprehensive review
of studies that have examined out-of-sample forecasting performance of various models
of volatility, conclude that “financial market volatility is clearly forecastable” but “as a rule
of thumb, historical volatility methods work equally well compared with more sophisticated
GARCH class and [stochastic volatility] models” (Poon and Granger, 2003). In contrast,
Ederington and Guan (2005) find that the GARCH model generally yields better forecasts
than the historic standard deviation and smoothing models. There are many other instances
where empirical findings have provided contradictory evidence.
This paper makes a further contribution to the literature by investigating the out-of-sample
predictive ability of the GARCH model in the context of foreign exchange markets. The data
cover a period of considerable change in these markets. The period studied is 1990 to 2004
which spans the introduction of the Euro, the move of several developing markets to open
economies, a significant depreciation on the US dollar and the Asian currency crisis of the late
1990s.
4
The purpose of this paper is to initially empirically assess the properties of foreign exchange
returns within the context of the applicability of GARCH models, and then attempt to forecast
the volatility of these returns in an out-of-sample exercise. Specifically, we examine the
forecasting power of the GARCH(1,1) model using time-series of daily spot exchange rates for
the Australian Dollar, British Sterling, French Franc, German Mark, Italian Lira, Japanese Yen,
Singaporean Dollar, Swiss Franc and Taiwan New Dollar. We demonstrate that the evaluation
of the out-of-sample predictions depends strongly upon the selection of the estimator for
latent volatility as well as the forecast error metric.
This remaining of this paper is organized as follows: Section 2 provides the background on the
models and their specification. Section 3 describes the data and the method. Section 4 presents
the empirical results while Section 5 concludes.
2. ARCH and GARCH models
Autoregressive Conditional Heteroscedasticity (ARCH) models, introduced by Engle (1982)
and generalised to GARCH by Bollerslev (1986), are models of conditional variance. In these
models, the variance is allowed to vary over time depending on the previous states of the
world (Bollerslev et al., 1994). The models represent an attempt to extract volatility from
historical observed returns. A stochastic process εt, parameterised by an unknown parameter(s)
5
θ, is said to follow a GARCH(p,q) process if its conditional mean equals zero conditioned on
the past information set It-1, and the conditional variance is specified as:2,3
( ) ∑∑=
−=
−−− σβ+εα+ω=ε≡σq
1i
2iti
p
1i
2iti1tt1t
2t I|Var t = 1, 2, … (1)
If all βi in (1) are zero, then the variance collapses to a function of the weighted average of past
squared innovations, as in the original ARCH model developed by Engle (1983).
The conditional distribution of εt is usually assumed to be normal (Bollerslev et al., 1994),
which is consistent with a heavy-tailed unconditional distribution.4
The simple GARCH(1,1) process has gained popularity and is perceived as a model that is
capable of capturing volatility clustering across various financial asset returns. As noted by
Engle, the GARCH(1,1) model is considered to be “a generally excellent model for a wide
2 Throughout this paper the dependence of tε and tσ on the parameter vector θ are suppressed for the
convenience of notation.
3 Only few processes have a constant mean of zero, so usually tε will be defined as the residual term from some
model, viz: γXYε 'ttt −= (Bollerslev et al., 1994).
4 As Bollerslev et al. (1994) note, “the degree of leptokurtosis induced by the time-varying conditional variance
often does not capture all of the leptokurtosis present in high frequency speculative process.” Thus, extensions
to ARCH andGARCH models have been proposed that allow for alternate conditional distributions including
the Student’s t-distribution (Bollerslev, 1987), power exponential distribution (Baillie and Bollerslev, 1989),
generalised error distribution (Nelson 1991) and normal inverse Gaussian (Barndorff and Nielsen, 1997).
6
range of financial data” (Engle, 1993). Yet numerous sophisticated modifications to the basic
model are available and these have tended to follow stylized facts observed in time-series of
financial returns.5 But while the ability of the GARCH models to fit the in-sample data well is
commonly praised, the out-of-sample forecasting power of these models remains questionable.
There have been a few attempts to forecast out-of-sample volatility but their conclusions vary
dramatically. For instance, ARCH models have been found to be an excellent forecasting tool
(Akgiray, 1989); but have also been reported to perform indifferently (Brailsford and Faff,
1996); and have been found to perform worse than a simple linear regression (Dimson and
Marsh, 1990).
The problem with forecasting volatility starts with the fact that the true underlying volatility is
unobservable. A common approach to estimating a proxy for ex-post volatility is to use the
squared return innovation over the relevant horizon. However, while the squared innovation
provides an unbiased estimate for the latent volatility factor, it can yield very noisy
measurements (Andersen and Bollerslev, 1998). Hence to eliminate noise, the more frequent
squared innovations 2tε are usually accumulated over some longer period to estimate the less
frequent latent volatility. For example, cumulative squared intra-day innovations are used to
estimate daily variances (Andersen and Bollerslev, 1998), or cumulative squared daily
innovations are used to estimate monthly variances (Figlewski, 1997).
5 An informative discussion of stylized facts and how they motivated researchers to examine new models can be
found in Bollerslev et al. (1994).
7
The other difficulty is that models generally “focus on variance one step ahead. They are not
designed to produce variance forecasts for a long horizon” (Figlewski, 1997). Thus, if there is
no new information, the series will converge to the long-run variance. Under the GARCH(1,1)
model, the forecast series can be obtained by:
21t
21t
2t −− βε+ασ+ω=σ
( ) ( ) ( ) 2t
2tt
21t
21tt EE σβ+α+ω=εβ+ασ+ω=σ −+
M
( ) ( ) ( ) 2t
k1k
0s
s2kttE σβ+α+β+αω=σ ∑
−
=+ (2)
From (2), it is clear that as the length of the forecast period increases, the model is likely to
become less accurate as there is no update of information. Thus, in practice, the model
requires re-estimation of the parameters with contemporary data to update information and
this can be cumbersome to apply as the update requires a sequence of models to be fitted over
a rolling sample of returns.
3. Data and Method
3.1. Data
The data consist of daily spot exchange rates for the currencies of Australia (AUD), France
(FRF), (West) Germany (DEM), Italy (ITL), Japan (JPY), Switzerland (CHF), Singapore
(SHD), Taiwan (TWD) and United Kingdom (GBP). These rates are all measured against the
8
US Dollar.6 The daily mid-rates were collected from Datastream for the period from 1 January
1990 to 30 July 2004. The sample comprises 3805 observations for each series (excluding
weekends). Plots of the data are presented in Figure 1. Consistent with prior literature, each
currency series follows a stochastic trend and exhibits no clear pattern.
[Figure 1 about here]
The sample period is partitioned into a twelve-year in-sample estimation period from 1 January
1990 to 31 December 2001 (3131 observations) and a subsequent out-of-sample forecasting
period from 1 January 2002 to 30 July 2004 (674 observations). The partitioning of the series,
though purely arbitrary, allows for a long estimation period as GARCH models rely upon a
relatively large number of data points for robust estimation. Of note, the in-sample period
includes the Asian financial crisis in 1997 and the introduction of the Euro in 1999, whereas
the out-of-sample period covers a strong depreciation of the US Dollar and the aftermath of
the events of September 11. Thus, the in-sample and out-of-sample periods cover different
economic conditions and this adds to the complexity of the forecast challenge.
Following Bollerslev et al. (1994), nominal percentage returns are computed, viz.:
( ) ( )[ ]1ttt YlnYln100X −−⋅≡ (3)
6 The rates for the ‘old’ European Union currencies (i.e. French Franc, German Mark and Italian Lira) were
obtained from Datastream and converted at the rates set by the European Central Bank on 31 December 1998.
9
where Yt is the mid-rate of the relevant exchange rate series relative to the US Dollar on day t.
It is a well-known stylized fact that exchange rate series have a unit root, whereby first
differences in logarithms of the spot rates are stationary. Confirmatory results are obtained for
each of the nine currencies under examination in this study. The results of the augmented
Dickey-Fuller (1979) tests for stationarity, with the null hypothesis of unit root, are presented
in Table 1. The table highlights that the nominal percentage returns (Xt) are stationary,7
whereas the raw series (Yt) is not stationary whether measured in levels or logarithmic scale.
[Table 1 about here]
Table 2 provides summary statistics of the (nominal) exchange rate returns. Separate sets
of descriptive statistics are presented for the in-sample, out-of-sample and full sample periods
(Panels A, B and C, respectively). The average return over the in-sample period is positive for
all currencies except Japan and Singapore (even though all median returns are zero).
In contrast, the average return over the out-of-sample period is negative for all currencies. This
feature highlights the differences between the in-sample of out-of-sample periods. Moreover,
even though the in-sample data set is almost five times larger than the out-of-sample data set,
the average return over the full sample period tends to be swamped by the smaller out-of-
sample period as indicated by the negative average return over the full period for most 7 A variable is said to be weakly stationary if the mean and autocovariances of the series are independent of time
(Brockwell and Davis, 2002).
10
currencies. Similarly, the various exchange rate returns tend to exhibit a tendency for negative
skewness over the in-sample period and positive skewness over the out-of-sample period.
[Table 2 about here]
Figure 2 plots the daily exchange rate returns. From this figure, there is visual evidence of
heteroscedastic attributes and the clustering of volatility can be seen. Further, leptokurtosis can
be seen in Figure 3. This figure contains the normal quantile-quantile plots for the daily
exchange rate returns. The plots posses the characteristic S-shape indicating that there is no
significant skewness, but the tails are heavier than a normal distribution (Andersen et al., 2000).
Overall, the data under analysis exhibit the common features consistent with the stylized facts
of exchange rate series previously documented (DeVries, 1994).
[Figure 2 about here]
[Figure 3 about here]
As discussed by Baillie and Bollerslev (1989), the fact that the unit root hypothesis cannot be
rejected for any of the currencies implies that the random-walk model as an explanation of rate
movements is inappropriate. Researchers have consequently looked for alternate time-series
models such as the ARCH family of models (Baillie and Bollerslev, 1989).8
8 Note that the method adopted herein implicitly treats each exchange rate as an independent series. In reality,
exchange rates are correlated and thus there is some argument for adopting a multivariate approach. However,
11
3.2. Estimation Method
Following Bollerslev et al. (1994), the conditional variance of each series is initially modeled
using an MA(1) – GARCH(1,1) process, viz:9
t1ttX ε+θε+μ= − (4)
t2
1t2
1t2t ν+βσ+αε+ω=σ −− (5)
Before the models are estimated, Engle’s (1983) test for ARCH effects is performed. Under
the null hypothesis, the variance from (5) is simply a constant and therefore the model (4) can
be estimated using ordinary least squares and the Lagrange multiplier test for p-th order
heteroscedasticity can be applied, as proposed by Breusch and Pagan (1980). Auxiliary
regressions are run of the squared OLS residuals 2tε , obtained from (4), on a constant and
squared p lags: 2pt
21t ε,...,ε −− , where p = 1, 4, 8. The number of observations (N-p) multiplied by
the R-squared of the auxiliary regression follows a chi-squared distribution with p degrees of
freedom under the null hypothesis of homoscedasticity.
as the focus in the paper is on forecasting each exchange rate and as they are separately examined, we leave
a multivariate approach for future work.
9 A set of day-of-week dummy variables was augmented to (4), to avoid any bias arising from the so-called
weekend effect (Baillie and Bollerslev, 1989). However, all coefficients on the day-of-week dummy variables
were insignificant. These results are not presented here but can be obtained from the authors.
12
The results of the tests for ARCH effects are provided in Table 3. The null hypothesis of white
noise errors is rejected in all cases at the 1% significance level for the in-sample period (Panel
A) and the full sample period (Panel C), consistent with a heteroscedastic structure in the
residuals. However, in the case of the out-of-sample period (Panel B), there is mixed evidence
of the rejection of the null hypothesis of homoscedasticity. In this period, the null hypothesis
is rejected at 8 lags for all series except Japan and Singapore, but the null hypothesis cannot
generally be rejected at lower lags. These mixed results may be due to the relatively short
length of the out-of-sample period, but are also consistent with earlier evidence that the in-
sample and out-of-sample periods exhibit different attributes.
[Table 3 about here]
3.3. Forecasting technique
Given the nature of the GARCH model, better forecasts should be attained when more
frequent squared innovations 2tε are cumulated to estimate less frequent (latent) volatility.
Therefore, we need to specify a period over which the individual forecasts are cumulated to
form the base for the evaluation. In the absence of any more logical frequency, we select
monthly intervals as the relevant evaluation frequency. Thus, we require monthly volatility
sequences for the out-of-sample period (1 January 2002 – 30 July 2004). We employ two
alternative procedures.
13
The first forecast series (F1) are obtained by employing the following procedure.10 First, using
parameter estimates obtained from the in-sample data, daily k-step ahead volatility forecasts
2stσ̂ + are generated using (2) for all trading days in the first month of the out-of-sample period.
Then, the monthly volatility forecast is formed by summing the k-step ahead daily forecasts,
i.e.:
∑=
+σ=σTN
1s
2st
2T ˆˆ (6)
Hence, initially we generate a set of daily forecasts for each trading day in January 2002 that
provides the monthly forecast for January 2002. The application of a rolling window then
moves the start and end dates of the in-sample estimation period forward one month such that
observations from January 1990 are deleted and observations from January 2002 are added to
the (in-sample) estimation period, and the estimation window remains at a constant length of
144 months. The procedure described above is then repeated to produce a volatility forecast
for February 2002. The window is then rolled forward one month at a time until a volatility
estimate is produced for July 2004 which is the last month in the out-of-sample period. Thus,
there are 31 forecasts that form the evaluation set over the period January 2002 to July 2004.
This consequent series of forecasts is based solely on ex-post data and there is no look-forward
bias in the forecasts. To this extent, the forecast method employed herein is capable of being
applied in practice.
10 A similar procedure has been used by Brailsford and Faff (1996), Wang and Wong (1997) and Figlewski (1997).
14
The second forecast series (F2) is similar except that we employ a different starting value for
the initial volatility point estimate. The k-step ahead daily forecasts under the GARCH model
as in (2), rely on both the parameter estimates and the initial point estimate of conditional
volatility which is itself reliant upon past innovations. Thus, if there is a consistent bias in the
innovations at the end of each period (month) then this will feed into the forecasts of the next
period (month). Moreover, in a small number of forecasts, spurious results may be obtained by
a few extreme end-of-period (month) values. Thus, we employ the average of the previous
month’s daily innovations in the initial estimate of the conditional variance, viz:
∑=
ε⋅=σTN
1t
2t
T
2t
N1 (7)
The conditional variance from (7) is used with the same parameter estimates as the first
method to produce daily k-step ahead volatility forecasts 2stσ̂ + using (2) for all trading days in
the first month of the out-of-sample period. Then, the monthly volatility forecast is formed by
summing the k-step ahead daily forecasts as per (6). The rolling window approach is again
applied to produce the series of monthly volatility forecasts.
Hence, the only difference between the two forecast methods is the starting estimate of the
conditional variance. As the second series (F2) relies upon an average value, a priori we expect
this forecast series to be smoother than the first series (F1) although we have no priors as to
how this will impact on forecast accuracy.
15
The forecasts need to be evaluated against actual volatility, however this variable is
unobservable. Previous studies have used a variety of proxies with the two main approaches
involving either realized volatility estimated from squared returns, or implied volatility reverse
engineered from option prices. The latter approach involves a joint assumption about market
efficiency and the validity of the pricing model which we wish to avoid. Moreover, implied
volatility itself has been used as the forecast estimator rather than the benchmark (eg. Day and
Lewis, 1992; Xu and Taylor, 1995). Hence we utilize observed returns to generate realized
volatility and construct the monthly volatility point by summation of the daily squared returns
over NT trading days in any month T, viz:
∑=
=σTN
1t
2t
2T X (8)
4. Empirical Results
4.1. Coefficient Estimates
Table 4 reports the estimated coefficients of the parameters in (4) and (5) together with their
robust standard errors computed using quasi-maximum likelihood methods (Bollerslev and
Wooldridge, 1992).11 From Table 4, the coefficient estimates of the conditional mean are all
insignificantly different from zero for all series. In contrast, the GARCH effects are significant 11 Note that the GARCH parameter estimates remain consistent even if the conditional normality assumption is
violated (providing the mean and variance functions are correctly specified), however, their standard errors will
be incorrect. Hence, suspecting non-normality, quasi-maximum likelihood estimators are used (Bollerslev and
Wooldridge, 1992).
16
as indicated by the highly significant coefficient estimates on α and β, providing further
support for the adoption of the model (at least for the in-sample period). Note that the sum of
the estimated GARCH parameters is close to the unity in all cases, showing a strong degree of
persistence in the conditional variance. 12 As noted by Anderson and Bollerslev (1989), this
suggests that “financial market volatility is highly predictable” so one might expect reasonably
accurate forecasts. However, the coefficients vary noticeably between the in-sample and out-
of-sample data, and it is this variation that makes point estimates difficult to predict.
[Table 4 about here]
Given the results in Table 4, and conscious of over-parameterisation, the MA(1) element is
dropped from the conditional mean equation in (4) and a more parsimonious model is re-
estimated.13 Moreover, as the conditional mean is insignificantly different from zero, the mean
of each series is assumed to be zero and therefore the estimation model collapses to the
conditional variance, viz:14,15
12 In such a situation, the Integrated GARCH model of Engle and Bollerslev (1986) could be employed to model
long-run volatility. However, this study is concerned with short-term volatility and thus avoids the use of
IGARCH (Andersen and Bollerslev, 1989).
13 These results are not presented here but can be obtained from the authors.
14 A similar approach is employed elsewhere (Brailsford and Faff, 1996; Andersen and Bollerslev, 1998);
Figlewski, 1997). These previous studies all report that the coefficients in the mean equation are insignificant,
and Figlewski (1997) finds that the assumption of a zero mean improves the out-of-sample forecast accuracy.
17
t2
1t2
1t2t X ν+βσ+α+ω=σ −− (9)
4.2. Forecast Results
Figure 4 plots the forecast and realized (monthly) volatility series for each of the nine
currencies over the out-of-sample period. A quick visual inspection reveals that the forecasts
from the second method (F2) that use an average as the initial estimate of conditional variance
each period provide a more accurate mapping of the realized volatility. Moreover, there
appears to be a general common trend between the forecast values and the realized volatility,
except in the case of Taiwan.
[Figure 4 about here]
However, Figure 4 provides only visual evidence and it is difficult to draw conclusions. Hence,
we turn to a more formal evaluation using error metrics to assess point estimates. A variety of
error metrics are available and have been previously used (see Brailsford and Faff, 1996; Byers
and Nowman, 1998). We select some common metrics that include the mean error (ME),
mean absolute error (MAE), root mean squared error (RMSE), mean absolute percentage error
(MAPE) and Theil’s inequity measure (U). These error metrics are defined as follows:
15 Note that a consequence of the forecast model relying only on the conditional variance as in (9) is that the
innovations tε in (7) become substituted by the returns, Xt.
18
( )∑=
−=KN
1T
2T
2T
K
σσ̂N1ME (10)
∑=
−=KN
1T
2T
2T
K
σσ̂N1MAE (11)
( )∑=
−=KN
1T
22T
2T
K
σσ̂N1RMSE (12)
( )∑=
−=KN
1T
2T
2T
2T
K
σσσ̂N1MAPE (13)
( )
( ) ( )∑∑
∑
==
=
+
−=
KK
K
N
1T
22T
K
N
1T
22T
K
N
1T
22T
2T
K
σN1σ̂
N1
σσ̂N1
U (14)
where NK is the total number of forecasts, i.e. 31.
The results of the application of the error metrics are reported in Table 5. While it is difficult
to draw an overall conclusion given the large number of results arising from multiple series and
multiple error metrics, the second method (F2) generally provides more accurate forecasts.
However, it should be noted that the evaluation of the forecast does vary a little dependent
upon the choice of the error metric. Nonetheless, there is a reasonably high degree of
consistency across the metrics that provide lower values for the second method across all
currencies. The difference in the two methods highlights a problem of forecasting with
GARCH especially over short periods, and the sensitivity of estimates to the starting values of
conditional variance.
19
[Table 5 about here]
We do not place much weight on the mean error (ME) in Table 5 as it allows the errors of
opposite signs to cancel each other. However, this metric does indicate whether volatility is
under- or over-predicted. From Table 5, the first method (F1) under-predicts the volatility of
Australian Dollar, Swiss Frank, German Mark, British Pound and Singapore Dollar and over-
predicts the remaining currencies, with the Yen giving rise to a notably large mean error. In
contrast, the second method (F2) only under-predicts two currencies being the Australian
Dollar and German Mark. In this case, the Taiwanese New Dollar is associated with a notably
large mean error.
The MAE presents a sobering set of statistics with both models exhibiting relatively high
measures. The second method (F2) is again preferred generally yielding error values around
half of those from the first method (F1). The worst cases appear to be the Australian Dollar
and Swiss Franc and the best cases are the Singapore Dollar and British Pound. The RMSE
metric provides a similar story.
Turning to percentage errors in the MAPE metric, which is arguably the most relevant for
practitioners, the second method (F2) is again generally preferred. However, when looking at
the individual currencies, the most accurate forecasts are obtained for the French Franc and by
far the worst are obtained for the Taiwan New Dollar. Theil’s statistic, which is bounded
between 0 and 1, is relatively low for all currencies using the second method (F2), with the
20
forecasts for the British Pound being the most accurate and for the Taiwan New Dollar being
the least accurate by a considerable margin. Also of note is that despite the fact that we have
used a GARCH model, the currencies that are the most difficult to forecast are those that
exhibited the largest levels of unconditional kurtosis.
The error metrics generally support the use of the second method (F2). Given that the two
forecast series differ only by the selection of the initial estimate of conditional variance each
period, it highlights the sensitivity of forecasts from the GARCH model as in (2) to these
initial estimates. The second method relies upon an averaging procedure over the prior month
which has the effect of smoothing the initial estimate across months and consequently
producing a smoother series of monthly forecasts. However, this does not a priori lead to
superior forecasts per se, however notwithstanding the results herein do support this method
as yielding superior forecasts.
5. Summary
This paper has examined the properties of the ARCH and GARCH model and their usefulness
in modeling and predicting the volatility of exchange rate returns. Initial examination of
foreign exchange rates from nine currencies with varying underlying economies revealed
ARCH effects and subsequent modelling using the GARCH model was undertaken. This
model was then used to generate out-of-sample volatility forecasts which were evaluated
against realized volatility. The approach was carefully constructed so to avoid any look-ahead
bias. Two series of forecasts were produced that varied through the initial estimate of
21
conditional variance for each period – an end-of-month point estimate and a month average
estimate. Through analysis of a series of error metrics, the method that utilizes the average of
the previous month was preferred, but this nonetheless generated errors of magnitude that
would be most likely be of concern to practitioners. While the results vary across currencies
and choice of metric, the out-of-sample analysis confirms how difficult it is to forecast
exchange rate movements. This is particularly so over the last few years in the Asian
currencies. A consequent message is that exposure to exchange rates must come with the
realisation that their unpredictable nature means that unpredictable gains and losses will be
incurred. As such, fund managers with international holdings must consider whether to hedge
their underlying returns or remain exposed to unpredictable exchange rate movements.
22
References
Akgiray, V., 1989, Conditional Heteroscedasticity in Time Series of Stock Returns: Evidence
and Forecast, Journal of Business 62, 55-80.
Andersen, T.G., 2000, Some Reflections on Analysis of High-Frequency Data, Journal of
Business & Economic Statistics 18, 146-153.
Andersen, T.G. and T. Bollerslev, 1998, Answering the Skeptics: Yes, Standard Volatility
Models do Provide Accurate Forecasts, International Economic Review 39, 885-905.
Andersen, T.G., T. Bollerslev, F.X. Diebold and P. Labys, 2000, Exchange Rate Returns
Standardized by Realized Volatility Are (Nearly) Gaussian, Multinational Finance Journal 4,
159-179.
Andersen, T.G., T. Bollerslev, F.X. Diebold and P. Labys, 2003, Modeling and Forecasting
Realized Volatility, Econometrica 71, 579-626.
Baillie, R.T. and T. Bollerslev, 1989, The Message in Daily Exchange Rates: A Conditional-
Variance Tale, Journal of Business and Economic Statistics 7, 297–305.
Ballie, R.T., T. Bollerslev and H.O. Mikkelsen, 1996, Fractionally Integrated Generalized
Autoregressive Conditional Heteroscedasticity, Journal of Econometrics 74, 3-30.
23
Barndorff-Nielsen, O.E., 1997, Normal Inverse Gaussian Distributions and Stochastic
Volatility Modelling, Scandinavian Journal of Statistics 24, 151-157.
Bollerslev, T., 1986, Generalized Autoregressive Conditional Heteroskedasticity, Journal of
Econometrics 31, 307-327.
Bollerslev, T., 2001, Financial Econometrics: Past Developments and Future Challenges,
Journal of Econometrics 100, 41-51.
Bollerslev, T., R.Y. Chou and K.F. Kroner, 1992, ARCH Modeling in Finance: A Review of
the Theory and Empirical Evidence, Journal of Econometrics 51, 5-59.
Bollerslev, T. and R.F. Engle, 1993, Common Persistence in Conditional Variances,
Econometrica 61, 167-186.
Bollerslev, T., R.F. Engle and D.B. Nelson, 1994, ARCH Models, in: R.F. Engle and D.L.
McFadden, eds., Handbook of Econometrics, Vol. 4. (North-Holland, Amsterdam), 2959-
3040.
Bollerslev, T. and J.M. Wooldridge, 1992, Quasi Maximum Likelihood Estimation and
Inference in Dynamic Models with Time Varying Covariances, Econometric Reviews 11, 143-
172.
24
Brailsford, T.J. and R.W. Faff, 1996, An Evolution of Volatility Forecasting Techniques,
Journal of Banking and Finance 20, 419-438.
Breusch, T.S. and A.R. Pagan, 1980, A Simple Test for Heteroscedasticity and Random
Coefficient Variation, Econometrica. 47, 1287-1294.
Brockwell, P.J. and R.A. Davis, 2002, Introduction to Time Series and Forecasting (Springer-
Verlag, New York).
Byers S.L. and K.B. Nowman, 1998, Forecasting U.K. and U.S. Interest Rates Using
Continuous Time Term Structure Models, International Review of Financial Analysis 7, 191-
206.
Day, T.E. and C.M. Lewis, 1992, Stock Market Volatility and the Information Content of Stock
Index Options, Journal of Econometrics 52, 267-287.
DeVries, C.G., 1994, Stylized Facts of Nominal Exchange Rate Returns, in: F. Van der Ploeg,
ed., Handbook of International Macroeconomics (Blackwell, Oxford).
Dickey, D. and W. Fuller, 1979, Distribution of the Estimators for Autoregressive Time Series
with a Unit Root, Journal of the American Statistical Association 74, 427–431.
25
Dimson, E. and P. Marsh, 1990, Volatility Forecasting Without Data-Snooping, Journal of
Banking and Finance 14, 399-421.
Ederington, L.H.. and W. Guan, 2005, Forecasting Volatility, Journal of Future Markets 25,
465-490.
Engle, R.F., 1982, Autoregressive Conditional Heteroscedasticity with Estimates of the
Variance of United Kingdom Inflation, Econometrica 50, 987-1008.
Engle, R.F., 1983, Estimates of the Variance of U.S. Inflation Based upon the ARCH Model,
Journal of Money, Credit and Banking 15, 286-301.
Engle, R.F., 1993, Statistical Models for Financial Volatility, Financial Analysts Journal 49, 72-
78.
Engle, R.F., 2002(a), Dynamic Conditional Correlation: A Simple Class of Multivariate
Generalized Autoregressive Conditional Heteroskedasticity Models, Journal of Business &
Economic Statistics 20, 339-350.
Engle, R.F., 2002(b), New Frontiers for ARCH Models, Journal of Applied Econometrics 17,
425-446.
26
Engle, R.F. and T. Bollerslev, 1986, Modelling the Persistence of Conditional Variances,
Econometric Reviews 5, 81-87.
Fama, E.F., 1965, The Behavior of Stock Market Prices, Journal of Business 38, 34-105.
Figlewski, S., 1997, Forecasting Volatility, Financial Markets, Institutions and Instruments 6, 1-
88.
Nelson, D., 1991, Conditional Heteroscedasticity in Asset Returns: A New Approach,
Econometrica 59, 347-370.
Poon, S.-H. and C. Granger, 2003, Forecasting Volatility in Financial Markets: A Review,
Journal of Economic Literature 41, 478-539.
Wang, J.-X. and H.-I. Wong, 1997, The Predictability of Asian Exchange Rates: Evidence from
Kalman Filter and ARCH Estimations, Journal of Multinational Financial Management 7, 231-
252.
Xu, X. and S.J. Taylor, 1995, Conditional Volatility and Informational Efficiency of the PHLX
Currency Options Market, Journal of Banking and Finance 19, 803-821.
27
Table 1 The Augmented Dickey-Fuller Test for Stationarity in Daily Exchange Rates
This table presents the results of the augmented Dickey-Fuller (1979) tests for stationarity of Australian Dollar (AUD), Swiss Franc (CHF), German Mark (DEM), French Franc (FRF), British Pound (GBP), Italian Lira (ITL), Japanese Yen (JPY), Singaporean Dollar (SHD) and Taiwan New Dollar (TWD) vs the US Dollar daily exchange rates. These are the daily mid-rates for the period from 1 January 1990 to 30 July 2004 for a total of 3805 observations excluding weekends. The tests, with the null hypothesis of unit root, are performed on the level and the logarithmic scales of the exchange rates directly as well as on the nominal percentage returns, calculated as (Bollerslev, Engle and Nelson, 1994):
( ) ( )[ ]1ttt YlnYln100X −−⋅≡
Auxiliary regressions are of the form: − t1t21t10t εYΔφYφφYΔ +++= −− for the level rates, − ( ) ( ) ( ) t1t21t10t εYlogΔφYlogφφYlogΔ +++= −− for the logarithms of the rates, − t1t0t εXφXΔ += − for the returns.
AUD CHF DEM FRF GBP ITL JPY SHD TWD
Exchange Rate Yt -1.5646 -2.0302 -1.4851 -1.5265 -2.0762 -1.4650 -2.3663 -1.8932 -0.7746 log(Yt) -1.5916 -2.0505 -1.5483 -1.5837 -2.0765 -1.4912 -2.2710 -1.7636 -0.8132
Return Xt -62.7691* -63.5218* -63.1896* -61.9879* -62.4215* -61.3127* -62.6009* -64.3975* -83.4224*
* denotes that the null of unit root is rejected at 1% significance level.
28
Table 2 Descriptive Statistics of Daily Exchange Rate Returns
This table presents the summary statistics of the daily nominal percentage exchange rate returns for the Australian Dollar (AUD), Swiss Franc (CHF), German Mark (DEM), French Franc (FRF), British Pound (GBP), Italian Lira (ITL), Japanese Yen (JPY), Singaporean Dollar (SHD) and Taiwan New Dollar (TWD) vs the US Dollar. Panel A presents the statistics for the in-sample period from 2 January 1990 to 31 December 2001 (3130 observations), Panel B the statistics for the out-of-sample period from 1 January 2002 to 30 July 2004 (674 observations). Panel C presents the statistics for the full sample period from 2 January 1990 to 30 July 2004 (3804 observations).
AUD CHF DEM FRF GBP ITL JPY SHD TWD
Panel A: 02 January 1990 – 31 December 2001
Mean 0.0138 0.0024 0.0084 0.0077 0.0033 0.0172 -0.0030 -0.0009 0.0094 Median 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
Std. Dev. 0.6131 0.7443 0.6828 0.6547 0.6138 0.6596 0.7379 0.3536 0.5137 Skewness -0.1291 -0.1349 -0.0521 -0.0636 0.1260 0.6687 -0.8686 -1.1300 0.0084Kurtosis 7.6403 4.9740 4.9420 5.7638 7.4068 10.0827 11.1978 24.618 14.651
Panel B: 01 January 2002 – 30 July 2004
Mean -0.0471 -0.0384 -0.0445 -0.0445 -0.0331 -0.0445 -0.0241 -0.0105 -0.0043
Median -0.0771 -0.0310 -0.0392 -0.0320 -0.0467 -0.0303 -0.0371 0.0000 0.0000Std. Dev. 0.7005 0.7122 0.6482 0.6225 0.5340 0.6232 0.5899 0.2863 0.2046 Skewness 0.5081 0.0535 0.1488 0.3326 0.2269 0.3339 0.1040 0.0908 0.8386 Kurtosis 4.4619 3.6068 3.4201 3.5277 3.9454 3.5311 4.0460 5.9674 8.3204
Panel C: 02 January 1990 – 30 July 2004
Mean 0.0031 -0.0049 -0.0010 -0.0015 -0.0032 0.0063 -0.0067 -0.0026 0.0070
Median 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 Std. Dev. 0.6298 0.7388 0.6770 0.6493 0.6005 0.6536 0.7139 0.3426 0.4739 Skewness 0.0133 -0.1029 -0.0175 0.0016 0.1456 0.6210 -0.7738 -1.0081 0.0332 Kurtosis 6.8158 4.7629 4.7113 5.4156 7.0882 9.1463 10.8321 23.470 16.697
29
Table 3 Tests for Heteroscedasticity in Daily Exchange Rates
This table presents the results of tests for ARCH effects, as proposed by Engle (1983), in daily nominal percentage exchange rate returns for the Australian Dollar (AUD), Swiss Franc (CHF), German Mark (DEM), French Franc (FRF), British Pound (GBP), Italian Lira (ITL), Japanese Yen (JPY), Singaporean Dollar (SHD) and Taiwan New Dollar (TWD) vs the US Dollar. Panel A presents the statistics for the in-sample period from 2 January 1990 to 31 December 2001 (3130 observations), Panel B the statistics for the out-of-sample period from 1 January 2002 to 30 July 2004 (674 observations). Panel C presents the statistics for the full sample period from 2 January 1990 to 30 July 2004 (3804 observations). The data are modeled using MA(1) – GARCH(1,1) process (Bollerslev et al., 1994), i.e.: t1tt εθεμX ++= − and t
21t
21t
2t νβσαεωσ +++= −− . Under the null hypothesis,
the variance 2tσ is a constant so the mean equation can be estimated using ordinary least squares and the Lagrange
multiplier test for p-th order heteroscedasticity can be applied, as proposed by Breusch and Pagan (1980). The auxiliary regressions are run on the squared OLS residuals 2
tε on a constant and squared p lags: 2pt
21t ε,...,ε −− , where
8,4,1p = . The number of observations (N - p) multiplied by the R-squared of the auxiliary regression follows a chi-squared distribution with p degrees of freedom under the null.
Test AUD CHF DEM FRF GBP ITL JPY SHD TWD
Panel A: 02 January 1990 – 31 December 2001
p=1 13.4441* 22.3214* 20.6166* 79.2260* 59.9106* 15.2240* 37.1575* 139.5807* 304.4138*
p=4 45.9187* 36.7563* 50.2281* 138.1219* 125.1219* 282.6219* 51.4313* 375.0906* 335.1719*
p=8 57.4860* 66.0092* 71.8423* 280.3438* 156.4120* 295.9301* 62.9381* 467.9690* 351.4933*
Panel B: 01 January 2002 – 30 July 2004
p=1 10.8730* 0.0007 0.8360 0.0679 1.7459 0.0564 4.0730** 0.3178 20.3038*
p=4 16.9772* 5.2670 8.4729 6.1796 15.5757* 6.1153 6.4953 1.0684 23.7187*
p=8 25.9922* 13.6637 23.6434* 19.8077** 26.2908* 19.8529** 12.0325 14.0268 92.4842*
Panel C: 02 January 1990 – 30 July 2004
p=1 22.4850* 24.2682* 18.3561* 78.7622* 69.1660* 16.2041* 46.0422* 167.2234* 380.2000*
p=4 57.3041* 40.4290* 54.7398* 147.3518* 151.8460* 316.1908* 64.2183* 442.3176* 422.9085*
p=8 76.0025* 73.3422* 81.1447* 304.1085* 189.6020* 329.4591* 77.8582* 554.5406* 445.4419*
* denotes that the null hypothesis of homoscedasticity is rejected at 1% significance level. ** denotes that the null hypothesis of homoscedasticity is rejected at 5% significance level.
30
Table 4 GARCH Model Parameters Estimates from Daily Exchange Rate Returns
This table presents the parameter estimates from fitting an MA(1) – GARCH(1,1) process (Bollerslev et al., 1994), i.e.: t1tt εθεμX ++= − and t
21t
21t
2t νβσαεωσ +++= −− . The model is applied to daily nominal percentage exchange
rate returns for the Australian Dollar (AUD), Swiss Franc (CHF), German Mark (DEM), French Franc (FRF), British Pound (GBP), Italian Lira (ITL), Japanese Yen (JPY), Singaporean Dollar (SHD) and Taiwan New Dollar (TWD) vs the US Dollar over the in-sample period from 2 January 1990 to 31 December 2001 (3130 observations). Robust standard errors are reported under the parameter estimates, and are computed using quasi-maximum likelihood methods (Bollerslev and Wooldridge, 1992). AUD CHF DEM FRF GBP ITL JPY SHD TWD
μ 0.0083 0.0059 0.0092 0.0045 -0.0064 0.0031 0.0045 -0.0078 0.0003 0.0100 0.0125 0.0113 0.0111 0.0098 0.0106 0.0119 0.0037** 0.0058 θ -0.0134 -0.0068 -0.0128 0.0186 -0.0159 0.0210 -0.0249 0.0153 -0.1890 0.0202 0.0190 0.0189 0.0191 0.0197 0.0205 0.0214 0.0217 0.0299* ω 0.0012 0.0124 0.0058 0.0054 0.0042 0.0039 0.0079 0.0009 0.0063 0.0010 0.0051* 0.0021* 0.0020* 0.0016* 0.0016** 0.0038** 0.0004* 0.0029**
α 0.0215 0.0315 0.0343 0.0389 0.0436 0.0555 0.0374 0.0858 0.2200 0.0052* 0.0078* 0.0069* 0.0079* 0.0118* 0.0144* 0.0115* 0.0180* 0.0460* β 0.9754 0.9455 0.9530 0.9482 0.9451 0.9371 0.9485 0.9089 0.7995 0.0072* 0.0139* 0.0084* 0.0097* 0.0135* 0.0150* 0.0152* 0.0213* 0.0355*
* denotes that a coefficient is significant at 1% significance level. ** denotes that a coefficient is significant at 5% significance level.
31
Table 5 Error Metrics from Forecasting Monthly Volatility using Out-of-Sample Exchange
Rate Returns
This table reports the error metrics from evaluating out-of-sample forecast series generated from the GARCH(1,1) model based on nominal percentage exchange rate returns statistics benchmarked against realized volatility for the French Franc (FRF), German Mark (DEM), Italian Lira (ITL), Japanese Yen (JPY), Swiss Franc (CHF) and British Pound (GBP) vs the US Dollar for the out-of-sample period from 1 January 2002 to 30 July 2004. The forecasts are of monthly volatility (31 estimates). Two forecast series are examined with the variation driven by the estimate of the initial conditional variance each period. The reported error metrics are the mean
error: ( )∑=
−=31
1T
2T
2T σσ̂
311ME , the mean absolute error : ∑
=
−=31
1T
2T
2T σσ̂
311MAE , the root mean squared
error: ( )∑=
−=31
1T
22T
2T σσ̂
311RMSE , the mean absolute percentage error: ( )∑
=
−=31
1T
2T
2T
2T σσσ̂
311MAPE , and
Theil’s inequity measure: ( )
( ) ( )∑∑
∑
==
=
+
−=
31
1T
22T
31
1T
22T
31
1T
22T
2T
σ311σ̂
311
σσ̂311
U
Variable AUD CHF DEM FRF GBP ITL JPY SHD TWD
Forecast Series F1
ME -0.000388 -0.000113 -0.000086 0.000024 -0.000136 0.000036 0.000293 -0.000037 0.000153MAE 0.000813 0.000921 0.000675 0.000700 0.000381 0.000729 0.000799 0.000160 0.000170RMSE 0.001091 0.001126 0.000854 0.000940 0.000523 0.000991 0.001264 0.000212 0.000192MAPE 0.007350 0.008595 0.007861 0.009138 0.005649 0.009472 0.012039 0.009128 0.054687
U 0.004434 0.004323 0.003975 0.004463 0.003803 0.004595 0.005247 0.004889 0.005005
Forecast Series F2
ME -0.000026 0.000013 -0.000002 0.000003 0.000004 0.000018 0.000057 0.000013 0.000207MAE 0.000437 0.000433 0.000373 0.000319 0.000206 0.000332 0.000297 0.000085 0.000209RMSE 0.000612 0.000593 0.000485 0.000399 0.000296 0.000413 0.000361 0.000126 0.000234MAPE 0.005086 0.004882 0.004487 0.003973 0.004182 0.004113 0.004821 0.004809 0.063197
U 0.002474 0.002463 0.002437 0.002188 0.002091 0.002234 0.002147 0.003000 0.005292
32
Figure 1 Daily Exchange Rates vs US Dollar 1990-2004
This figure plots the series of daily exchange mid-rates for the Australian Dollar (AUD), Swiss Franc (CHF), German Mark (DEM), French Franc (FRF), British Pound (GBP), Italian Lira (ITL), Japanese Yen (JPY), Singaporean Dollar (SHD) and Taiwan New Dollar (TWD) vs the US Dollar over the period 2 January 1990 to 30 July 2004 for a total of 3805 observations excluding weekends.
1.0
1.2
1.4
1.6
1.8
2.0
2.2
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
AUD
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
CHF
1.2
1.4
1.6
1.8
2.0
2.2
2.4
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
DEM
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
FRF
.45
.50
.55
.60
.65
.70
.75
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
GBP
1000
1200
1400
1600
1800
2000
2200
2400
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
ITL
60
80
100
120
140
160
180
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
JPY
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
SHD
24
26
28
30
32
34
36
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
TWD
33
Figure 2 Volatility of Daily Exchange Rate Returns 1990-2004
This figure plots the daily nominal percentage exchange rate returns for the French Franc (FRF), German Mark (DEM), Italian Lira (ITL), Japanese Yen (JPY), Swiss Franc (CHF) and British Pound (GBP) vs the US Dollar for the period from 2 January 1990 to 30 July 2004 (3804 observations).
-6
-4
-2
0
2
4
1990 1992 1994 1996 1998 2000 2002 2004
AUD
-4
-3
-2
-1
0
1
2
3
4
1990 1992 1994 1996 1998 2000 2002 2004
CHF
-4
-3
-2
-1
0
1
2
3
4
1990 1992 1994 1996 1998 2000 2002 2004
DEM
-5
-4
-3
-2
-1
0
1
2
3
4
1990 1992 1994 1996 1998 2000 2002 2004
FRF
-6
-4
-2
0
2
4
6
1990 1992 1994 1996 1998 2000 2002 2004
GBP
-4
-2
0
2
4
6
8
1990 1992 1994 1996 1998 2000 2002 2004
ITL
-8
-6
-4
-2
0
2
4
6
1990 1992 1994 1996 1998 2000 2002 2004
JPY
-5
-4
-3
-2
-1
0
1
2
3
1990 1992 1994 1996 1998 2000 2002 2004
SHD
-5
-4
-3
-2
-1
0
1
2
3
4
1990 1992 1994 1996 1998 2000 2002 2004
TWD
34
Figure 3 Quantile-Quantile Plots of Daily Exchange Rate Returns
This figure presents the normal quantile-quantile plots for the daily nominal percentage exchange rate returns for the French Franc (FRF), German Mark (DEM), Italian Lira (ITL), Japanese Yen (JPY), Swiss Franc (CHF) and British Pound (GBP) vs the US Dollar for the period from 2 January 1990 to 30 July 2004 (3804 observations).
Normal Quantiles
Qua
ntile
s of
AU
D
-2 0 2
-8-6
-4-2
02
46
Normal Quantiles
Qua
ntile
s of
CH
F
-2 0 2
-8-6
-4-2
02
46
Normal Quantiles
Qua
ntile
s of
DE
M
-2 0 2
-8-6
-4-2
02
46
Normal Quantiles
Qua
ntile
s of
FR
F
-2 0 2
-8-6
-4-2
02
46
Normal Quantiles
Qua
ntile
s of
GB
P
-2 0 2
-8-6
-4-2
02
46
Normal Quantiles
Qua
ntile
s of
ITL
-2 0 2
-8-6
-4-2
02
46
Normal Quantiles
Qua
ntile
s of
JP
Y
-2 0 2
-8-6
-4-2
02
46
Normal Quantiles
Qua
ntile
s of
SH
D
-2 0 2
-8-6
-4-2
02
46
Normal Quantiles
Qua
ntile
s of
TW
D
-2 0 2
-8-6
-4-2
02
46
Figure 4 Comparison of Realized and Forecast Volatility of Monthly Exchange Rate Returns
This figure presents a comparison of the realized volatility with out-of-sample forecast series generated from the GARCH(1,1) model based on nominal percentage exchange rate returns statistics benchmarked against realized volatility for the French Franc (FRF), German Mark (DEM), Italian Lira (ITL), Japanese Yen (JPY), Swiss Franc (CHF) and British Pound (GBP) vs the US Dollar for the out-of-sample period from 1 January 2002 to 30 July 2004. The forecasts are of monthly volatility (31 estimates). Two forecast series are examined with the variation driven by the estimate of the initial conditional variance each period. The dotted line graphs forecast series F1; the dashed line graphs the forecast series F2; the solid line graphs the corresponding realized volatility.
Vol
atili
ty
2001Dec
2002Jun
2002Dec
2003Jun
2003Dec
2004Jun
510
1520
25
AUD
Vol
atili
ty
2001Dec
2002Jun
2002Dec
2003Jun
2003Dec
2004Jun
510
1520
CHF
Vol
atili
ty
2001Dec
2002Jun
2002Dec
2003Jun
2003Dec
2004Jun
510
15
DEM
Vol
atili
ty
2001Dec
2002Jun
2002Dec
2003Jun
2003Dec
2004Jun
48
1216
FRFV
olat
ility
2001Dec
2002Jun
2002Dec
2003Jun
2003Dec
2004Jun
26
1014
GBP
Vol
atili
ty
2001Dec
2002Jun
2002Dec
2003Jun
2003Dec
2004Jun
48
1216
ITL
Vol
atili
ty
2001Dec
2002Jun
2002Dec
2003Jun
2003Dec
2004Jun
46
812
16
JPY
Vol
atili
ty
2001Dec
2002Jun
2002Dec
2003Jun
2003Dec
2004Jun
12
34
5
SHD
Vol
atili
ty
2001Dec
2002Jun
2002Dec
2003Jun
2003Dec
2004Jun
01
23
4
TWD