Strange Days July 20'th, 2011 Back to Table Of Contents At 09:34:06, all quotes from PACF (NYSE ARCA) for Nasdaq stocks stopped updating. For a subset of these stocks, quotes from PACF stopped earlier. At 09:40:25, PACF sent zero-priced quotes for 2,818 Nasdaq stocks, which removed PACF from the NBBO. At 10:04:13, PACF resumed sending quotes. During the entire period from market open through quote resumption at 10:04:13, trades were reported executing at PACF. During the time that quotes stopped updating from PACF, the last quote from PACF became "stuck" at the NBBO (either bid or offer side, depending on where the stock was trading). Trades executed at PACF at both the "stuck" price, as well as what appeared to be normal prices. NYSE Arca quoting problem affects 2,818 stocks during first 35 minutes of trading. Shown below are 4 of those stocks. AMTD - AMERITRADE HOLDINGS Price and Size: Price Only: Price Only: Price Only: RVBD - RIVERBED TECH Price and Size: Price Only: Price Only: Price Only: EBAY - EBAY Price and Size: Price Only: Price Only: BIDU - BAIDU Price and Size: Price Only: Price Only: Price Only: Inquiries: pr@nanex.net Publication Date: 07/20/2011 http://www.nanex.net This report and all material shown on this website is published by Nanex, LLC and may not be reproduced, disseminated, or distributed, in part or in whole, by any means, outside of the recipient's organization without express written authorization from Nanex. It is a violation of federal copyright law to reproduce all or part of this publication or its contents by any means. This material does not constitute a solicitation for the purchase or sale of any securities or investments. The opinions expressed herein are based on publicly available information and are considered reliable. However, Nanex makes NO WARRANTIES OR REPRESENTATIONS OF ANY SORT with respect to this report. Any person using this material does so solely at their own risk and Nanex and/or its employees shall be under no liability whatsoever in any respect thereof.