Strange Days Aug 29th, 2011 Back to Table Of Contents On August 29, 2011 over a 4 second period beginning at 12:19:48, there were 44,939 quotes from one exchange in one stock: NVIDIA (symbol NVDA). All but 14 of these quotes set the NBBO. There were exactly zero trades. During this period, these NVDA quotes accounted for 81% of all NBBO quotes for all NYSE, AMEX, ARCA, and Nasdaq equities. The algorithm appears to be the same one that caused excessive quotes in Dell on August 25th. We hereby award the originator of this mess the HFT Pig Award. The Chart below shows the percentage of quotes and NBBO quotes in NVDA compared to quotes from all stocks. NVDA - NVIDIA, Price and Sizes Zoom in of sequence: Inquiries: pr@nanex.net Publication Date: 08/29/2011 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.