The Securities and Exchange Commission ("Commission") is adopting new Rule 13h-1 and Form 13H under Section 13(h) of the Securities Exchange Act of 1934 ("Exchange Act") to assist the Commission in both identifying, and obtaining trading information on, market participants that conduct a substantial amount of trading activity, as measured by volume or market value, in the U.S. securities markets. Rule 13h-1 will require a "large trader," defined as a person whose transactions in NMS securities equal or exceed 2 million shares or $20 million during any calendar day, or 20 million shares or $200 million during any calendar month, to identify itself to the Commission and make certain disclosures to the Commission on Form 13H. Upon receipt of Form 13H, the Commission will assign to each large trader an identification number that will uniquely and uniformly identify the trader, which the large trader must then provide to its registered broker-dealers. Such registered broker-dealers will then be required to maintain records of two additional data elements in connection with transactions effected through accounts of such large traders (the large trader identification number, and the time transactions in the account are executed). In addition, the Commission is requiring that such broker-dealers report large trader transaction information to the Commission upon request through the Electronic Blue Sheets systems currently used by broker-dealers for reporting trade information. Finally, certain registered broker-dealers subject to the Rule will be required to perform limited monitoring of their customers' accounts for activity that may trigger the large trader identification requirements of Rule 13h-1. The large trader reporting requirements are designed to provide the Commission with a valuable source of useful data to support its investigative and enforcement activities, as well as facilitate the Commission's ability to assess the impact of large trader activity on the secu