Could it have been some sort of “STOP BUY” order ? I have seen “stop LOSS” orders executed that way ..its called running the stops .
I had a “stop Loss”done that way in Copper one time..Copper was trading at .51-.53 for a long time and had not been below that in memory ..I put a stop at .49
they reached down and took out my stop and copper never looked back on its way to 1.50 I missed out on a bunch of money ! I never used a stop again !