“Once such traders were treated as participants their transactions did not meet the objective criteria determining the scope of the right to deduct”
“If he knows or should have known that the contra-trader is engaging in fraudulent conduct and deals with him, he takes the risk of participating in a fraud, the precise details of which he does not and cannot know”
“The nature of contra-trading is easy to state [in terms of clean and dirty chains] but the problem in real life is that there is no logical connection between the clean and dirty chains”