Saturday, January 31, 2009

Impressive Financial Forecasting with SVR


A couple of researchers (Li, Hu, and Hirosawa) have displayed pretty interesting findings forecasting the USD/JPY exchange rate via a Support Vector Regression (SVR) network. The file explains the details. Let's break down what they did and accuracy results from the empirical test.

Basic idea of SVR: Nonlinear mapping of data into a high dimensional feature space with a kernel function, then do a linear regression in the transformed space. It all results in a nonlinear regression in low dimensional space.


Inputs of their study:

f(t): Historical USD/JPY exchange rate

F(t): Historical USD/EUR exchange rate

N(t): Historical NIKKEI 225 stock index value

O(t): Historical oil price in USD


Predicted Value (Output): USD/JPY exchange rate at the next day (t+1), next week (t+5), and 2 weeks from now (t+10)

Prediction evaluation tools:

Sum of Square Error (SSE)

Mean Absolute Error (MAE)

SSE and MAE measure deviation between actual and forecasted values, so the smaller the better the accuracy of forecasts.I find the MAE more practical of course since it isn't squared.


Correct Up Trend (CP)

Correct Down Trend (CD)

CP and CD basically gives the probability of forecast being correct for the next-day USD/JPY direction. So higher is better.


The results compared those of conventional SVR models and SVR network:

USD/JPY

Stat

SVR

SVR N

f(t+1)

sse

47.3925

36.2098


mae

0.1672

0.1471


cp

76.8116

77.8468


cd

79.4118

79.8039





f(t+5)

sse

60.5918

38.4611


mae

0.1877

0.152


cp

76.7635

79.668


cd

78.3465

79.3307





f(t+10)

sse

71.5295

39.7972


mae

0.2052

0.1544


cp

77.453

80.167


cd

78.937

79.9213



So we can see that this is impressive for both SVR and especially the SVR Network. Directionally it's correct close to 80% of the time and an average error of within 0.15 Yen (with respect to daily range), for all three time frame predictions.


A lot of people don't look at this stuff because it takes a lot of thinking, so they convince themselves that it "doesn't work anyway". Well I'm here to tell you that IT DOES.





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