Notional. Those contracts have between 8-15x leverage. Looking at the CNBC graph linked you can see the volume better (though not the actual lot sizes). The likely at risk dollars was probably closer to 10M across both.
Sure, I believe that. But not 580 Billion. (I sometimes wonder how much damage has been done to the United States political system by naming them million, billion and trillion. Would we all budget carefully and precisely consider the relative impacts of different scales of expenditure if a thousand thousand was a woozle, a thousand woozle added up to a brillig, and a thousand brillig was a fearsome vogon?)