Reuters has dug up some of the the trading volumes in futures from 1:09-1:12 pm ET as a fake tweet from the hacked AP twitter account caused a gigantic blip in markets.
- 260,000 front month S&P e-mini contracts traded (about 13% of avg. daily volume)
- 180,000 front month 10-year Treasury futures contracts traded
The notional value of the S&P contracts would be around $20 billion, if my math is correct, and the notional of the T-note futures would have been $18 billion.
That`s just two contracts and it`s notional, not gains and loses but it shows how it would be nearly impossible to track down anyone who traded it. Shorting for 10 points on 1000 e-mini contracts is worth $750,000. Trading something 10 times that size in FX would have been entirely undetectable.