A New York Stock Exchange filing to eliminate limitations on program trading order entry procedures contained in NYSE Rule 80A became effective on November 2. The rule was rescinded because, according to the Exchange, “it did not appear that the approach to market volatility envisioned by the use of these “collars” is as meaningful today as when the rule was formalized in the late 1980s” in response to the market break of 1987. Recent trading patterns led the Exchange to conclude that volatility was “neither restrained nor enhanced” by the imposition of the collars.

http://www.sec.gov/rules/sro/nyse/2007/34-56726.pdf

http://apps.nyse.com/commdata/PubInfoMemos.nsf/AllPublishedInfoMemosNyseCom/85256FCB005E19E8852573860054C408/$FILE/Microsoft%20Word%20-%20Document%20in%2007-106.pdf