Why do trades close out by them selves?

 
I make a buy order but do not put in a TP or SL number, come back a little later and the order is closed at a loss! What gives?
 
your equity was too low. Position has been closed automatically by the broker.
 
GarF1eld wrote >>
your equity was too low. Position has been closed automatically by the broker.

Thanks that makes sense.