On May 25th, the SEC provided notice of the national securities exchanges' joint filing of a plan to address extraordinary market volatility. The proposal would create a market-wide limit up-limit down mechanism intended to address extraordinary market volatility in National Market System ("NMS") Stocks, as defined in Rule 600(b)(47) of Regulation NMS under the Securities Exchange Act. The proposal sets forth proposed procedures that provide for market-wide limit up-limit down requirements that would be designed to prevent trades in individual NMS Stocks from occurring outside of the specified Price Bands. These limit up-limit down requirements would be coupled with Trading Pauses, as defined by the proposal, to accommodate more fundamental price moves (as opposed to erroneous trades or momentary gaps in liquidity). Comments should be submitted on or before June 22, 2011. SEC Release No. 34-64547.