sorry your post on 6587 says
"For instance, in your example, what if the underlying EU price went from 1.4049-1.4050, to 1.4040-1.4050, and then back to 1.4049-1.4050 without trading lower than 1.4049? Your quote would QUITE CLEARLY be an error, so a trade could be incorrectly stopped out. How would the average punter be able to know the truth? Seems like a fundamental flaw to me."
errrr do you actually read what you write? If the underlying market goes to 1.4040-1.4050 then ummm... that is the real underlying market. There is no error. Do you want LCG to quote this price? Widening our price out to 10 pips? Because this is what actually happened in the real market. Why is our price "clearly an error"?
why would our price of 1.4045-1.4046 be wrong? Just because nobody actually trades at 1.4040 does not make the quote incorrect. All market activity moving from one price to the next ends with either a price going offered (or bid) but the bid below it (offer above it) not being traded OR with the bid (offer) holding steady, trading at the price but not going offered (bid).
Just because a bid / offer spread in the real market might not trade does not mean that Capital Spreads should not move its price.
i.e. if the FTSE future goes 5880-5881 to 5879-5880 and then back to 5880-5881 but 5879 never trades are you suggesting that we should not move our price to 5879-5880 to reflect the market move?
anyway we will have to agree to disagree on this subject
Simon