im an idiot 
It’s common for brokers to bank your profit, or subtract your loss from your account on a trade left open from one day to the next.
The new level your trade is at is just where the trade closed on the change of days.
Not every broker does it, but it’s certainly not unheard of.
I was shocked the first time I had it happen to me too;)
I had left trades open overnight on my demo, and it had never happened.
It was a little odd to see my trade in a different place…
My broker charges a swap fee I don’t know how it is worked out. It usually amounts to a few cents each night a trade is left open