samtron said:Nasdaq:
Does anyone know what causes the charts from tws to display price spikes (too many to be just line breaks), these spikes are completely absent on charts from other vendors.
Also they do not appear in the time and sales listings for the chart.?
I am not certain of what the real answer is but I have had innumerable issues with this problem with TWS - including trades that turned into losers. The data you get for your chart and the data in the TWS window ARE different! I have spent hours on the phone with IB and their tech people have been next to useless. Here is my theory that I think makes sense. Perhaps others on these boards can substantiate this further.
I believe (and have heard so from others) that the IB feed is not timestamped. Thus, your charting software must determine the boundaries of the bars or candles based on your PC clock which drifts and is notoriously inaccurate. This is a huge issue if you are using tick charts or volume bars for your trading. Furthermore, IB does not send you true data. They filter the data and send you only 2/3 to 3/4 of the actual trades. For example, the ratio between IB ticks and Esignal ticks is about 3.1 so 100 IB ticks is about the same as 310 ESignal ticks. This affects volumes which I have heard can be out by as much as a factor of 10. Also, historical IB data is apparently filtered in 2 sec intervals - not good if you trade off of tick charts or volume bars. There are several solutions. One, synchronize your PC clock to a known time source every 30 min or so; two, don't use tick charts; three, don't rely on volumes or four, get a true timestamped data feed. I am in the process of getting a new feed. I've had too many trades go bad on account of poor IB data. Hope this helps.
Cheers
Paul