Here some random excerpt from today (500 volume chart). The differences on a volume bar chart (compared to a tick chart) are minor. I'm not sure if they have a significant impact on your trading result If you rely on a tick chart for your trading style, subscribe to a superior datafeed. If you use volume charts, IB's feed is probably just fine (no need to spend the extra money)... IB:
So you just found out that you cannot plot accurate tick charts by using a snapshot data feed... no shit Sherlock! Thanks for the precious info
It's not about knowing that a snapshot feed is inaccurate (which is notorious) but about actual seeing the real difference on a chart...
yeah sure... you wrote: "I have been trading with IB's datafeed for quite a while now. Unfortunately I was always too lazy to evaluate another feed. Today I subscribed to the 7 day trial from IQ... Like expected, the snapshot feed from IB is "useless" around critical points, i.e. opening, major reports etc. It's up on the individual trader if he can cover the expenses with the better accuracy from IQ's feed..." Sorry dude, it's quite evident you've been using or you wanted to use IB for plotting tick charts, or that post wouldn't make any sense. IB datafeed is notorious for its accuracy around ,as you call them, "critical points" in virtue of its snapshot nature. IOW, it doesn't lag compared to tick by tick datafeeds. Now if you try to plot a tick chart, no wonder you don't have a real tick chart. Doh! That doesn't mean IB is not a more than decent datafeed. It means you need to use a tick by tick data feed to plot a tick chart. period
I wouldn't say it's evident... Funny is, that I trade and will ever trade only with volume charts! The reason why I opened this thread was, that there are always some discussions (on ET as well as on German boards) in which the difference between IB's datafeed and a true tick by tick feed is discussed. But nobody has ever made a printsreen of the two feeds with different chart types so that everybody can easily see the point. So it was pure curiosity and in no means linked to my personal trading. I was also aware, that the two feeds are not of the same category. Nevertheless you can made a little comparison to see, what's the benefit of a pricier feed over the IB feed which is free. The fact that some guys thanked for the comparison states, that this thread is not useless... At least it doesn't need a big discussion as the bottom line is clear - I think we understand each other... good trades, D.
I use IB as a data feed but not as a broker, for the reasons pointed out earlier. My broker gets good fills but not great. At some point I may consider spending buku bucks every month for better data, but I've run the math and my own data source comparisons from trial periods have not seen enough of a gap to legitimize spending time and money on changing anything.
I have never used IB nor IQ but as a professional trader, I certainly appreciate the information that you shared. I found it very interesting.
I made today a confrontation between 4 feeds: DTN.IQ, IB, ZEN and PhotonTrader (TT?) I looked only, how fast price changes were trasmitted. And surprise, surprise, IB was mostly the fastest. DTN was the slowest (esp. on EUREX). IB does not send every tick (but also Photon does not it seems ) but the important thing, the changes in price are faster on your charts.... Looking at ticks, ZEN is without doubt the best.