# Neural Network Stock price prediction - Extremely accurate results

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Hi,

I have implemented a narxnet neural network to predict the next day closing price of stocks. I have been conducting this experiment for Offshore Stocks on the Singapore Exchange. The problem I am having is that Neural Network is giving extremely accurate results for prediction with Mean Absolute error in the range of 5*E^-3 to 7*E^-3. I am not able understand if the Neural Network really so accurate in predicting stock prices, or if I have been making some mistake in the implementation of the ANN. I am using 60% Data for Training, 5% Validation and 35% Testing and Early Prediction to predict the performance. Please could you have a look at the code below and suggest where I am going wrong?

if true

%code

clc, clear

Stock_names = {'CAO' 'CHO' 'CHW' 'DMHL' 'ezion' 'EZRA' 'falcon' 'keppel' 'KS' 'SCI' 'SMM' 'swiber'};

b = Stock_names{2};

data=csvread(strcat(b,'.csv'), 1,1);

inputSeries = tonndata(data(1:end,2:end),false,false);

targetSeries = tonndata(data(1:end,1),false,false);

mae = zeros(3,1);

mape= zeros(3,1);

rmse = zeros(3,1);

msre = zeros(3,1);

start = int32(5);

last = int32(9);

for k = 1: %loop for iteratively increasing the hidden layers by 5

Performance_Matrix5 = zeros(5,4);

s = strcat('D', int2str(start), ':', 'G', int2str(last));

for j = 2:6 % looping through number of delays from 2 to 6

for i = 1:3 % loop for taking average of results for each iteration

inputDelays = 1:j;

feedbackDelays = 1:j;

hiddenLayerSize = 5*k; %hiddenlayer neurons

net = narxnet(inputDelays,feedbackDelays,hiddenLayerSize);

net.inputs{1}.processFcns = {'removeconstantrows','mapminmax'};

net.inputs{2}.processFcns = {'removeconstantrows','mapminmax'};

[inputs,inputStates,layerStates,targets] = preparets(net,inputSeries,{},targetSeries);

net.divideFcn = 'divideblock'; % Divide data randomly

net.divideMode = 'value'; % Divide up every value

net.divideParam.trainRatio = 60/100;

net.divideParam.valRatio = 5/100;

net.divideParam.testRatio = 35/100;

net.trainFcn = 'trainlm'; % Levenberg-Marquardt

net.performFcn = 'mse'; % Mean squared error

net.plotFcns = {'plotperform','plottrainstate','plotresponse', ...

'ploterrcorr', 'plotinerrcorr'};

% Train the Network

[net,tr] = train(net,inputs,targets,inputStates,layerStates);

% Test the Network

outputs = net(inputs,inputStates,layerStates);

errors = gsubtract(targets,outputs);

performance = perform(net,targets,outputs);

% Recalculate Training, Validation and Test Performance

trainTargets = gmultiply(targets,tr.trainMask);

valTargets = gmultiply(targets,tr.valMask);

testTargets = gmultiply(targets,tr.testMask);

%trainPerformance = perform(net,trainTargets,outputs)

%valPerformance = perform(net,valTargets,outputs)

%testPerformance = perform(net,testTargets,outputs);

% Closed Loop Network

netc = closeloop(net);

[xc,xic,aic,tc] = preparets(netc,inputSeries,{},targetSeries);

netc.name = [net.name ' - Closed Loop'];

yc = netc(xc,xic,aic);

closedLoopPerformance = perform(netc,tc,yc);

N_closedLoopPerformance = closedLoopPerformance/mean(cell2mat(tc));

%Early Prediction

nets = removedelay(net);

nets.name = [net.name ' - Predict One Step Ahead'];

[xs,xis,ais,ts] = preparets(nets,inputSeries,{},targetSeries);

ys = nets(xs,xis,ais);

earlyPredictPerformance = perform(nets,ts,ys);

c1 = cell2mat(ts);

c2 = cell2mat(ys);

b1 = c1(:,1:(end-1));

b2 = c2(:,1:(end-1));

N_earlyPredictPerformance = earlyPredictPerformance / mean(b1);

% error calculation through ereperf.m external file

MAE_ep = errperf(b1, b2, 'mae');

MAPE_ep = errperf(b1, b2, 'mape');

RMSE_ep = errperf(b1, b2, 'rmse');

MSRE_ep = errperf(b1, b2, 'msre');

% disp('Next day closing price was forecasted to')

% ys(end)

% figure

% plot([cell2mat(yc);cell2mat(tc)]')

% legend('Network Predictions','Expected Outputs')

% figure

% plot([cell2mat(ys);cell2mat(ts)]')

% legend('Network Predictions','Expected Outputs');

mae(i) = MAE_ep;

mape(i)= MAPE_ep;

rmse(i) = RMSE_ep;

msre(i) = MSRE_ep

end

Performance_Matrix5(j-1,1) = mean(mae);

Performance_Matrix5(j-1,2) = mean(mape);

Performance_Matrix5(j-1,3) = mean(rmse);

Performance_Matrix5(j-1,4) = mean(msre);

xlswrite(strcat(b, '_results.xlsx'), Performance_Matrix5, s);

end

end

start = start+ 6;

last = last + 6;

end

I have looped through a range of hidden neurons, and delays corresponding to each iteration of the hidden neuron like a trial and error for getting the best configuration. I have used both closeloop net and early prediction for predicting the stock price but the MAE, RMSE, MAPE error seem to be absurdly small which is extremely difficult for stock market prediction due to its efficiency. I have also uploaded the csv file with the stock data 'CHO.csv' if you would like to test the network out. Where have I gone wrong?

The Matlab Program outputs the results for each iteration of changing hidden neurons and delay to an excel file. The errperf.m file contains external error measurements.

##### 2 Comments

Rajesh Vemulapalli
on 31 Oct 2017

Pls mail me @rajeshvemulapalli1997@gmail.com detail explaination of this code.

### Answers (3)

Greg Heath
on 9 Apr 2015

% Neural Network Stock price prediction - Extremely accurate results

% Asked by Soham Acharjee about 10 hours ago

% Hi,

% I have implemented a narxnet neural network to predict the next day

% ...

% with Mean Absolute error in the range of 5*E^-3 to 7*E^-3. I am not able

That means nothing unless the scale of the data is known

% understand if the Neural Network really so accurate in predicting stock

% ...

% I am using 60% Data for Training, 5% Validation and 35% Testing

Strange division combination ... Why?

% and Early Prediction to predict the performance.

Although can get OPENLOOP early prediction when min(TARGET feedback delay) = 1

CANNOT get CLOSELOOP early prediction when min(OUTPUT feedback delay) = 1

%Please could you have a look at the code below and suggest

% where I am going wrong?

% ...

%

% Stock_names = {'CAO' 'CHO' 'CHW' 'DMHL' 'ezion' 'EZRA' 'falcon' 'keppel' ...

% 'KS' 'SCI' 'SMM' 'swiber'};

% b = Stock_names{2};

% data=csvread(strcat(b,'.csv'), 1,1);

% inputSeries = tonndata(data(1:end,2:end),false,false);

% targetSeries = tonndata(data(1:end,1),false,false);

[I N ] = size(inputSeries) % = ?

[ O N ] = size(targetSeries) % = ?

whos data inputSeries targetSeries ?

% mae = zeros(3,1);

mae is the name of a MATLAB function

% mape= zeros(3,1);

% rmse = zeros(3,1);

% msre = zeros(3,1);

What is msre ?

start = int32(5);

last = int32(9);

Why the need for int32 ?

% for k = 1: %loop for iteratively increasing the hidden layers by 5

ERROR: k = 1 : ?

% Performance_Matrix5 = zeros(5,4);

% s = strcat('D', int2str(start), ':', 'G', int2str(last));

s = D5:G9 What does that mean ???

% for j = 2:6 % looping through number of delays from 2 to 6

% for i = 1:3 % loop for taking average of results for each iteration

% ...

% net.inputs{1}.processFcns = {'removeconstantrows','mapminmax'};

% net.inputs{2}.processFcns = {'removeconstantrows','mapminmax'};

Why include mapminmax defaults?

% [inputs,inputStates,layerStates,targets] = preparets(net,inputSeries,{},targetSeries);

% ...

% net.divideParam.valRatio = 5/100;

% net.divideParam.testRatio = 35/100;

Weird division. Why this choice?

% net.trainFcn = 'trainlm'; % Levenberg-Marquardt

% net.performFcn = 'mse'; % Mean squared error

% net.plotFcns = {'plotperform','plottrainstate','plotresponse', ...

% 'ploterrcorr', 'plotinerrcorr'};

Why include? These are defaults.

% % Train the Network

% [net,tr] = train(net,inputs,targets,inputStates,layerStates);

No output states ? ... How to predict beyond data ?

% ...

% % Closed Loop Network

% netc = closeloop(net);

% [xc,xic,aic,tc] = preparets(netc,inputSeries,{},targetSeries);

% netc.name = [net.name ' - Closed Loop'];

% yc = netc(xc,xic,aic);

% closedLoopPerformance = perform(netc,tc,yc);

% N_closedLoopPerformance = closedLoopPerformance/mean(cell2mat(tc));

Reference MSE should be mean(var(cell2mat(tc)',1)

What is the numerical difference betwen open loop and closed loop answers?

% %Early Prediction

% nets = removedelay(net);

Only works for OPENLOOP

% Where have I gone wrong?

Dunno

##### 2 Comments

Greg Heath
on 14 Apr 2015

Neural Network Stock price prediction - Extremely accurate results

% Asked by Soham Acharjee about 10 hours ago

% ... with Mean Absolute error in the range of 5*E^-3 to 7*E^-3.

>> That means nothing unless the scale of the data is known

> The range of data is from 0.3 to 1.5

It helps, immensely to ALWAYS scale data BEFORE training. Then, regardless of the problem and data source, you can be familiar with the range of numbers at different stages in the design. I prefer to scale with ZSCORE to detect outliers and estimate significant auto and cross correlation lags usin NCORR.

> ... Therefore I am iteratively increasing the output and feedback > delay from 2 to 6 (loop j)

You can estimate, DIRECTLY, significant correlation lags using NNCORR

>> whos data inputSeries targetSeries ?

>The 'data' is obtained after the file CHO.csv (attached) is read using the command

Sorry, what I meant is to cut and paste that whos statement (without the "?") into the command line to verify dimensions and class

% % Train the Network

% [net,tr] = train(net,inputs,targets,inputStates,layerStates);

>>No output states ? ... How to predict beyond data ?

Can use [ net tr y e Xof Aof ] = train(neto,... ... % % Closed Loop Network % netc = closeloop(net); % [xc,xic,aic,tc] = preparets(netc,inputSeries,{},targetSeries); % netc.name = [net.name ' - Closed Loop']; % yc = netc(xc,xic,aic); % closedLoopPerformance = perform(netc,tc,yc); % N_closedLoopPerformance = closedLoopPerformance/mean(cell2mat(tc));

>>Reference MSE should be mean(var(cell2mat(tc)',1)

>>What is the numerical difference betwen open loop and closed loop answers?

>Open loop performance: 1.0441e-04 >closed loop performance: 6.6112e-04 >early predict performance: 6.5612e-05

>Configuration (Input delays: 3, feedback delays: 3, hidden neurons: 5)

Brian Whatcott
on 31 Aug 2016

##### 0 Comments

David Willingham
on 5 Oct 2020

Hi,

If the intent is to forecast price to make trading decisions, I suggest looking at this example on GitHub:

This example shows how to teach an RL Agent to learn to buy, sell or hold based on historical data. The reward function has been setup to reward when a trade doesn't result in a loss.

Regards,

##### 0 Comments

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