Yesterday, the NYSE published an Information Memorandum to answer frequently asked questions concerning proposed NYSE Rule 80C and NYSE Amex Equities Rule 80C, which would enable the NYSE to "pause trading in an individual security listed on the exchange if the price moves by 10% as compared to prices of that security in the preceding five-minute period during a trading day." If approved by the SEC, the circuit breaker rule will be tested on a pilot basis beginning June 7, 2010 and ending on December 10, 2010, and will apply to "those individual securities in the S&P 500 Index." During the pilot period, the NYSE will "continue to assess whether additional securities need to be added and whether the parameters of the [proposed] rule should be modified." Last week's filing of the proposed rules with the SEC and yesterday's Information Memorandum are responses to the intraday stock market plunge and related "market disruption" and "extraordinary market volatility" that occurred on May 6.