what a nonsense. Each big fx option trade and subsequent hedge or larger cash position is reflected on the tape. Give or take some pips, depending which price feed you are looking at you see exactly the same big orders that sometimes move markets when liquidity is not at its hight than what you see in the index futures or commodities futures markets. So your argument is pretty flawed imho.
Quote from Ivanovich:
Far harder. In the FX market, the little guy operates outside the flow of the money and has zero visibility to the flow until it's passed.