Contrary Opinions March 9, 2001 Perry J. Kaufman Contrary opinion alone is not meant to signal a new entry into a position; it only identifies situations that qualify. It lacks the timing. It is more of a filter than a trading system, a means of avoiding risk and finding an opportunity. –-Perry J. Kaufman, from Trading Systems and Methods, 3rd edition (1998, John Wiley & Sons, New York).