Thursday, August 16, 2018

Create stock portfolio on Google Sheets using SGX price data

18 Oct 2019: Please refer to this link for the updated post on how to create stock portfolio using SGX price Data.

It used to be very easy to create your SGX stock portfolio on Google Sheets as we can rely on Yahoo Finance or even Google Finance data. However, this changed when both stop the services. As such, the next best thing is to just rely on SGX daily price file which is available after market close. However, to automatically update your Google Sheets with this data is no longer a simple process. Below i share my steps on how i download the SGX price list from within Google sheets, do some data formatting and use formula to update the stock price accordingly.

1. Create a new Google Sheets and click "Script Editor" under Tools menu.


2. Paste the following code and click save. If you have issue with the code below like incorrect special character, please copy the code from this link.

function onOpen() {
  var spreadsheet = SpreadsheetApp.getActive();
  var menuItems = [
    {name: 'Import SGX data...', functionName: 'importSGX'},
  ];
  spreadsheet.addMenu('Import', menuItems);
}

function importSGX() {
  var spreadsheet = SpreadsheetApp.getActive();
  var dataSheet = spreadsheet.getSheetByName('Data');
  dataSheet.activate();
   
  // Since the data is only available after market close
  // codes below will make sure when it is run before market close, pick yesterday date
  // Current assumption is data is available after 6pm
  var todayDateTime = new Date();
  var currentHour = todayDateTime.getHours();

  if (currentHour >= 18) {
    var dataDate = Utilities.formatDate(new Date(), "GMT+8", "yyyy-MM-dd");
    Logger.log(dataDate);
  }else{
    var MILLIS_PER_DAY = 1000 * 60 * 60 * 24;
    var now = new Date();
    var dataDate = Utilities.formatDate(new Date(now.getTime() - MILLIS_PER_DAY), "GMT+8", "yyyy-MM-dd");
    Logger.log(dataDate);
  }

  var importString = "http://infopub.sgx.com/Apps?A=COW_Prices_Content&B=SecuritiesHistoricalPrice&F=5254&G=SESprice.dat&H=" + dataDate;
  
  // import SGX price list data into datasheet
  var csvUrl = importString;
  var csvContent = UrlFetchApp.fetch(csvUrl).getContentText();
  var csvData = Utilities.parseCsv(csvContent,';');
  
  dataSheet.getRange(1, 1, csvData.length, csvData[0].length).setValues(csvData);
  
  // Check if data is correct, if there is valid data, cell(1,1) won't be blank.
  // If there is valid data, split the data using ; delimiter.
  var checkValidData = dataSheet.getRange(1,1);
  if (!checkValidData.isBlank()){
    
    var startRow = 1;
    var endRow = dataSheet.getLastRow();
   
    // Get the range value for stock codes, convert all the values to string and trim it.
    // Withut trim, matching could be troublesome because you need to
    // manually add space so to match
    var range = dataSheet.getRange("O1:O");
    var rangeValues = range.getValues();
    range.setNumberFormat("@");
    
    for (var i = startRow; i <= endRow; i++) {
       // accessing the array data, array start from 0, that's why need to put i-1
       var data = rangeValues[i-1][0];
       dataSheet.getRange(i,15).setValue(String(data).trim());
      }
   }
}

3. There will be prompt to Edit Project Name. Just put any name.


4. Go back to your Google Sheets and reload the browser.  After reload, you should be able to see a new menu called Import appear.


5. Create a new sheet and named it "Data". After rename, click on Import > Import SGX data...


6. When run this script for the first time, Google Sheets will prompt Authorisation Required message. Just click Continue and follow the processes to allow script to run. Once it is done, you can see the Data sheet populated with SGX price list data.


7. Go back to first sheet and you can now use formula to match stock quotes (column O) and retrieve the share last done price (column G). Below is the sample table structure for the portfolio sheet.


This is the formula used on Last Done Price column, B2 is cell for stock quotes.

=INDEX(Data!$G$1:$G$1066, MATCH (B2, Data!$O$1:$O$1066, 0))

8. You can also configure trigger to have this script run at certain time everyday. Again go to Script editor and under Edit menu, click Current project's trigger.


9. Click on No trigger set up. Click here to add one now.


10. Select importSGX function to run, Time-driven, Day timer event with time set to 6:00 p.m. to 7:00 p.m. and click Save. And this will make this script run between 6 pm to 7 pm daily.


So that's it, you can start construct your own portfolio for for your shares in SGX.