@Ashige
Most shares trade on SETS which stands for the Stock Exchange Electronic Trading Service,
the London Stock Exchange’s digital order book. SETS facilitates most of the
orders on the LSE. SETS qx (where BCN is traded), or Stock Exchange Electronic
Trading Service – quotes and crosses, is a variant of SETS that is used for
securities that aren’t liquid enough for SETS.
There are auctions that are scheduled to take place at 8 am, 9 am, 11 am, 2 pm and 4:35 pm. For some stocks, there are market makers who will offer prices on a fixed bid/offer spread while the market is open.
Usually, if there’s enough demand/liquidity, the orders would go through the auction. It appears that hasn’t been the case recently. I’m guessing that the broker you made the order with either internalized the trade (off-book) or traded with a market maker. Trading with a market maker is a manual process which may involve phone calls or manual electronic call. Both of these would
necessitate some discretion on the part of the broker – whether to accept a price whereas executing an order in an auction period means there is no market spread and buyers and sellers should receive the same price.
We’ll look at what we can do to improve this though.