Potential Data Problems

Occasionally I get an email saying that a prospective trade has triggered but doesn't appear in open trades or that it suddenly disappeared from open trades and isn't in closed trades - what has happened?

These things are extremely difficult to nail down.  The key thing is that SwingTrader is like any other computer program, very black and white.  Either the calculations have been coded correctly in which case they are correct in every instance or they have been coded incorrectly in which case you get a consistent error.  SwingTrader has been used extensively for over 2 ½ years and the latest significant code revision was almost a year ago.  If there was a consistent error (bug or miscalculation) in the code I am pretty sure we would have known about it well before now.  So mostly I have to assume that the code (program) is in good shape in which case when we get the odd error such as the ones mentioned above have to assume (from a remote position without being able to reproduce the issue) that it is a data error from Yahoo or Google. 

Data errors do happen in all data feeds whether free or subscription and often they go unnoticed because they are not hooked into a computer program like SwingTrader where this data is used for calculations and displayed.  Generally these data errors are corrected fairly quickly and that is why very occasionally you can get for example, a prospective trade showing one day and the next day the trade has disappeared from SwingTrader completely.  This is easy to understand when you consider that for example the close on a particular day is x which causes the price to be 0.01 above the MA but when the close price is corrected to y the price is 0.01 below the MA.  With price x a prospective trade will show but with price y it will not. Computer programs are black and white, it either is a yes or a no, no judgment is made in the way we humans will say “It’s a boarder line case”.

Each day SwingTrader takes fresh data from Yahoo or Google and calculates ALL trades (prospective, open and closed) afresh so the data has to be consistent to allow a trade to progress from prospective to open trades. If today it is calculated that there was a prospective trade that triggered yesterday then it will be in open trades but if TODAY there was no prospective trade yesterday or it wasn't triggered yesterday then it will not be in open trades even if YESTERDAY it was in prospective trades and appeared to trigger (due to some incorrect data). 

I hope I have explained that clearly.

If you feel that there is a genuine bug in SwingTrader please check it out thoroughly to be as sure as you can that it is not a temporary data error then send me as much detail and screen grabs as possible immediately together with the event log and Watch List file.  See the main trouble shooting page for details on how to do this.