FAQ: Where can I find beta’s?

In Datastream you can find the current beta (a measure of the volatility of a share) with datatype Mnemonic BETA in a static request. Worldscope and Thomson Financial also offer their current beta (available with the Excel add-in). The method of calculation is different in these three databases, so check the definition and calculation method!

An example of the beta from Worldscope (WS), Thomson Financial (TF) and Datastream (DS) for Google and TomTom.

Historical beta’s are more difficult to get. Datastream offers a historical beta (Mnemonic = 897E) , but you have to check their calculation method to see if you agree with this method. Datastream uess a five year period, and the share price is regressed “against the respective Datastream total market index using log changes of the closing price on the first day of each month”. Which Datastream total market index is used, can be retrieved from Datastream, by requesting in a static request the datatype Assoc Market Index – Datastream (Mnemonic = INDX) of the equity.

More information about the calculation of the historical beta by Datastream can be found in Extranet: http://extranet.datastream.com/Codes/Economics/69Chan/69Beta.htm When you have to login, please use the creditials used for Datastream Navigator.

Worldscope data in Datastream

The database Worldscope offers annual and quarterly report data, like sales, net income and total assets. This data can be accessed with the Thomson One Banker Excel add-in.

Worldscope data is also, but partly, available inDatastream. If you want to download this data from Datastream, please note the following:

  • We only have access to the data items in bold. When you select in Datastream Navigator a non-bold item, you’ll get an error message for that item in your output. In most cases, the non-bold data items can be downloaded from Thomson. Unfortunately you can’t search by WC code in the Excel add-in of Thomson, but you can check this WC code in the definition of the items in the Excel add-in of Thomson.
  • If you want quarterly data, you have to select the correct datatype in Datastream. In Datastram Navigator check at the top of the screen what is selected behind Worldscope Report Type: If you want quarterly data, you have to change Annual into All or Interim to find the datatype and select the Interim datatype (with the A at the end of the Mnemonic). In most cases Interim means quarterly, but it can also mean semi-annual.
    When you select the annual datatype and request the data on a quarterly basis in Datastream, you will see that the annual value is repeated for each quarter. Please note: You won’t be able to see this when you change the currency in Datastream (due to changes in the exchange rate).

Worldscope & DS2

Non-trading days in Datastream

This week the New York Stock Exchange was closed for two days, due to Hurricane Sandy. How does Datastream deal with these non-trading days?

When you download for example the Closing Price (Datatype P) the closing price of the previous trading day, in this case October 26, will be repeated. If you want no data when there was no trading, you have to use a different datatype: P#S. This will give you ‘unpadded data’, for example when the exchange is closed due to a holiday or the stock is suspended and thus no stock price is published.

New release of Datastream Navigator

This week Datastream Navigator changed a bit:

  • You can find the codes of individual future contracts in Datastream Navigator in the Data Category ‘Futures’ (like AEX Index mar 2013), and lists of living or dead futures in the Data Category ‘Constituents Lists’.
  • The Explore option has moved, you can find it in the black bar on top of the Search page. This Explore options is a guided search.
  • When you use the Search option, and click on a code you see a overview of the information for that stock or index. This now includes for example a link to the constituent lists where the stock belongs to.
  • When you use the Search option, you’ll get a list of 10 results, to see result number 15 you have to go to the next page. Now, when the total number of results is less than 400, you’ll find a link Show all in the right upper corner.

FAQ: risk free interest rates

It can be difficult to find risk free interest rates. You can’t find them under that name in Datastream, so what do you have to choose?

Datastream offers an overview of the instruments they recommend for the main markets, including the Datastream code . This overview is available on the Extranet of Datastream, this is the link. When you have to login use the username and password of Datastream Navigator.

Please note: these series are recommended by Datastream, for your own research purpose you might have to choose other series.

Enhancements to Datastream Navigator – Options

In the new version of Datastream Navigator one Data Category has changed a lot: the category ‘Options’. From now you can find the mnemonics of the individual option contracts (call or put, with their own expiry dates and exercise prices) in Datastream Navigator. (Previously you could only see them on a computer with a Datastream connection in a small pop-up screen.)

For example:

The number of option contracts can be quite overwhelming, especially when you include dead options to the results. For example: there are 864 live call options for the S&P 500 in Datastream! 

TIP: to make sure you find the options you’re looking for, you can first search the DS Mnemonic of the underlying instrument (the index, commodity, stock etc) and enter this Mnemonic in the search field  ‘Underlying Mnemonic’ of the Advanced Search in  the Option part of Datastream Navigator.

When you want to download data for all option contracts of a certain option, it might be easier to work with lists. These can now be found in the Data Category ‘Index Constituents’. In general, each option has four lists: live call options, live put options, dead call options and dead put options.

With the DS Mnemonic of the list you can download the Static and Time Series information of the underlying option contracts in one request in Datastream.

See our updated manual for more information.

Enhancements to Datastream Navigator – Searching & Finding

Datastream Navigator has been enhanced. Important changes in searching and finding the codes you need to download data from Datastream are:

  • The Explorer function that was available for some Data Categories, like Economics, is no longer available. The Explorer is now incorporated in the Search option: you’ll see a small link Explore under the search bar. The Advanced Search, where you can search with particular fields, is still available.
  • When you use Search to find your series, you can use the column at the left side of the results (under Refine Search) to filter by include or by excluding certain search options. Click the +/- link to get this list.
  • Interest Rates and Exchange Rates are deleted from the Economics part of the Navigator. Of course these series can still be found in the specific data categories Interest Rates and Exchange Rates.
  • In some cases you’ll see a small excel icon at the right side of the grey All results bar. This allows you to quickly download the names and mnemonics of the list of series on your screen.

Rebasing indices in Datastream

Under the Function button in Datastream a lot of useful options are hidden. One of them is the option to rebase an index: you can choose the date this index is rebased to 100.

These are the steps you have to take:

  • Open Time Series Request in Datastream
  • Enter the code of the index or use Find Series to find the code
  • Click behind Datatypes/Expressions the Fx-button
  • Search for Rebase
  • Use for example REB#(expression,date) and click OK

  • Enter the date behind Date (in this format: dd/mm/yyyy)
  • Click OK – the function is entered behind Datatypes/Expressions

  • Enter your start- and enddate
  • Click Submit – the data download starts

Error message in Economics part of Datastream Navigator

If you want to search for the codes of macro-economic indicators in the Economics module of Datastream Navigator, you probably get this error message after hitting the Search Now button.

As far as we know this only happens in the Economics module. This message can appear when you use the online version of Datastream Navigator and in the Excel add-in of Datastream (the Find Series button).

The solution: You can solve this by deleting the cookies and the temporary internet files in Internet Explorer (Tools > Internet Options > button delete under Browsing History).

Downloading stockprices centered around a particular date

When you need stockprices centered around a particular date, for example the announcement of a merger or a CEO change, you can use the Datastream Event Study Matching Tool (available on our website, you need an ERNA-account to access it). For this tool you need a list of identifiers Datastream can recognize (DSMnenomics, DS Codes, ISIN-codes or SEDOL-codes), the dates, in a format like 10-16-2007, and a computer with a Datastream connection. Behind Estimation window and Event window you have to specify the number of days around the event.

If your list only contains US companies you can also use a tool in CRSP:  this tool is called ‘Daily Extract with Time Window’. You can find it in CRSP Annual Update under Tools. Here you need a text-file with the PERMNOs and the event date (in YYYYMMDD format – see picture below). Under Window Size you have to specify the number of days before and after the event. Don’t forget to mark Company Name and Price.