Hi
It depends on if you are trading selections or betting or dutching.
If you use the stop loss settings, then yes match unmatched bets
but you will need to tick either a time or a price condition below that.
this will match your unmatched bet at best available price depending on available liquidity.
say you have backed 100 at 4.3 and it is unmatched
money available on back side at 4.2 is 60
money available on back side at 4.1 is 120
your 100 will be matched as
60 at 4.2
40 at 4.1
also worth looking at other ways of matching unmatched bets:
trigger actions:
trade out
match unmatched back bets
match unmatched lay bets