This didn't cost me money, rather hoping I can understand it so I don't make the mistake in future where it could.
Buy limit order, Nasdaq, placed during market close with a popular Australian online broker..
Few hours later just about when Nasdaq was very close to open (~ 1:30AM AEDT), I cancelled the order, verified no errors and there was no longer an order in place, and went to sleep.
Wake up the next day to a confirmation email. My order was fulfilled when my limit price was eventually hit 5 hours after market open,
Order log showed 5 entries: Creating, Amending, Cancelling, Traded, Finished.
So had to enquire with broker.
A week later after it gets passed in deeper, they tell me "cancellation was unsuccessful because the cancellation of the order was attempted during a non-cancel period."
Wouldn't the broker then just cancel the order after such a period? Or is this some anti-cold-feet protection mechanism?