Sell Limit not executed but price reached

[Drmole]

I placed a sell order on Synairgen today could not get a quote so place a Limit order at 175 Price at that time was about (160-175)  about 1 hour late i am checking my order and see the price is (185-195) and has been higher but order has not executed why is this.

[knicol46]

Synairgen is a market maker stock and uses the SETSqx trading system.  There is no order book.   Any limit order would only execute if a matched limit order was uncrossed and executed at auction uncrossing times.   These are 0800, 0900, 1100, 1400 and 1635.  Even though you wanted to sell @ 175p and if the sell price was say 200p+ it would still not automatically execute if using limit orders - only if your trade was uncrossed (not crossed out) at auction uncrossing time would it execute.   

https://www.lseg.com/sites/default/files/content/documents/LSEG_SETSQX_FACTSHEET_1.PDF

[Guest RobJ]

I've had this twice now recently. Last night my limit was hit twice at around 5am. Both times the limit didn't trigger. Confidence in this platform is dropping for me.

[Guest CakeyDave]

Just had the same thing happen to me twice on Gold and in fact it did it a few times previously, but luckily I'm still using a demo account.