Hi Spread-Bettor, during the past 2 weeks, I have found one occasion on the chart with a greater than average movement of price compared to two other spread betting companies. Thank you for your comment as it has made me recall this incident. At the time I was thinking about placing limit orders to take advantage of such movements. But you have reminded me that such spikes can affect you badly.
Sadly I cannot quantify the spike. It was not greater than 20 pips I think. If anyone has the data, could someone check as I have the date and the price of the peak. I should have recorded the peak for the other two companies. It was EURUSD, 2nd May 2014, time 7:55 which I believe is European time so 8:55 UK time. The peak price: 1.3862. I confirmed with them that the movement is valid. It was a spike up and then down so a maximum.
At the time I remember the incident to be just mildly shocking because it was not too big to be shocking but not too small to be blatantly obvious. I hope someone can check the peak with a different data provider.