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.